Enable the compile-time option MBEDTLS_AES_ROM_TABLES in the mbed TLS
main config.h file in mbed OS. This option has the effect of labelling
the AES tables as 'const' so they are placed in ROM, which saves some
RAM space.
Update the current version of mbed TLS with the development HEAD of the
mbed TLS project repository. This mostly includes the latest CMAC
feature. Also, update the version in the importer Makefile and
VERSION.txt with the hash of the mbed TLS commit that was sync'ed.