This commit add following crypto changes
1. Update current crypto code with upstream supplicant code
2. Add a proper porting layer to use mbedtls APIs for all the crypto
operations used by supplicant.
Internal crypto will be used when USE_MBEDLTS flag is disabled
in supplicant's menuconfig.
This commit also removes the clutter in crypto files due to partial
porting of some APIs to mbedtls, all the code from those files have
been removed and rewritten in a generic way, this is inspired from
current upstream code.
This also reduces the lib size significantly, supplicant's lib
size reduces around ~567kb after this change(NB: lib size doesn't
indicate reduction in final bin size).
