* fix compilation warning
* adjust SHA3-384 test error-codes
The way the codes were constructed before, they were not unique.
* unify code
Instead of having `ifdef`'s in the code, define our own wrapper around
the keysource as required.
* add CMake option for help-text in wolfCrypt tests
* expose test `main()` as `wolfcrypt_test_main()`
* Don't overwrite previously set errors
* add FreeRTOS support for Xilinx demo
* move `fp_reverse` from `tfm.c` to `wolfmath.c` and rename to
`mp_reverse`.
Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>