Remove Yotta support from the docs, tests and build scripts

Yotta is no longer supported by Mbed TLS, so has been removed. Specifically, the
following changes have been made:
 * references to yotta have been removed from the main readme and build
   instructions
 * the yotta module directory and build script has been removed
 * yotta has been removed from test scripts such as all.sh and check-names.sh
 * yotta has been removed from other files that that referenced it such as the
   doxyfile and the bn_mul.h header
 * yotta specific configurations and references have been removed from config.h

README.md

@@ -11,47 +11,16 @@ Compiler options can be set using conventional environment variables such as `CC
 Compiling
 ---------
 
-There are currently four active build systems used within Mbed TLS releases:
+There are currently three active build systems used within Mbed TLS releases:
 
--   yotta
 -   GNU Make
 -   CMake
 -   Microsoft Visual Studio (Microsoft Visual Studio 2010 or later)
 
 The main systems used for development are CMake and GNU Make. Those systems are always complete and up-to-date. The others should reflect all changes present in the CMake and Make build system, although features may not be ported there automatically.
 
-Yotta, as a build system, is slightly different from the other build systems:
-
--   it provides a minimalistic configuration file by default
--   depending on the yotta target, features of Mbed OS may be used in examples and tests
-
 The Make and CMake build systems create three libraries: libmbedcrypto, libmbedx509, and libmbedtls. Note that libmbedtls depends on libmbedx509 and libmbedcrypto, and libmbedx509 depends on libmbedcrypto. As a result, some linkers will expect flags to be in a specific order, for example the GNU linker wants `-lmbedtls -lmbedx509 -lmbedcrypto`. Also, when loading shared libraries using dlopen(), you'll need to load libmbedcrypto first, then libmbedx509, before you can load libmbedtls.
 
-### Yotta
-
-[yotta](http://yottabuild.org) is a package manager and build system developed by Mbed, and is the build system of Mbed OS 16.03. To install it on your platform, please follow the yotta [installation instructions](http://docs.yottabuild.org/#installing).
-
-Once yotta is installed, you can use it to download the latest version of Mbed TLS from the yotta registry with:
-
-    yotta install mbedtls
-
-and build it with:
-
-    yotta build
-
-If, on the other hand, you already have a copy of Mbed TLS from a source other than the yotta registry, for example from cloning our GitHub repository, or from downloading a tarball of the standalone edition, then you'll first need to generate the yotta module by running:
-
-    yotta/create-module.sh
-
-This should be executed from the root Mbed TLS project directory. This will create the yotta module in the `yotta/module` directory within it. You can then change to that directory and build as usual:
-
-    cd yotta/module
-    yotta build
-
-In any case, you'll probably want to set the yotta target before building unless it has already been set globally. For more information on using yotta, please consult the [yotta documentation](http://docs.yottabuild.org/).
-
-For more details on the yotta/Mbed OS edition of Mbed TLS, including example programs, please consult the [Readme at the root of the yotta module](https://github.com/ARMmbed/mbedtls/blob/development/yotta/data/README.md).
-
 ### Make
 
 We require GNU Make. To build the library and the sample programs, GNU Make and a C compiler are sufficient. Some of the more advanced build targets require some Unix/Linux tools.
@@ -78,7 +47,7 @@ In order to build for a Windows platform, you should use `WINDOWS_BUILD=1` if th
 
 Setting the variable `SHARED` in your environment will build shared libraries in addition to the static libraries. Setting `DEBUG` gives you a debug build. You can override `CFLAGS` and `LDFLAGS` by setting them in your environment or on the make command line; compiler warning options may be overridden separately using `WARNING_CFLAGS`. Some directory-specific options (for example, `-I` directives) are still preserved.
 
-Please note that setting `CFLAGS` overrides its default value of `-O2` and setting `WARNING_CFLAGS` overrides its default value (starting with `-Wall -W`), so it you just want to add some warning options to the default ones, you can do so by setting `CFLAGS=-O2 -Werror` for example. Setting `WARNING_CFLAGS` is useful when you want to get rid of its default content (for example because your compiler doesn't accept `-Wall` as an option). Directory-specific options cannot be overriden from the command line.
+Please note that setting `CFLAGS` overrides its default value of `-O2` and setting `WARNING_CFLAGS` overrides its default value (starting with `-Wall -W`), so if you just want to add some warning options to the default ones, you can do so by setting `CFLAGS=-O2 -Werror` for example. Setting `WARNING_CFLAGS` is useful when you want to get rid of its default content (for example because your compiler doesn't accept `-Wall` as an option). Directory-specific options cannot be overriden from the command line.
 
 Depending on your platform, you might run into some issues. Please check the Makefiles in `library/`, `programs/` and `tests/` for options to manually add or remove for specific platforms. You can also check [the Mbed TLS Knowledge Base](https://tls.mbed.org/kb) for articles on your platform or issue.