RSE: Rename TRNG tests to Random generation

The way random generation is exposed by the BL1 shared library is
now different and not strictly related to the TRNG access, hence
rename the tests to reduce confusion.

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: Iac23fe736e7cb40c3a6bacc6793f53be96122590
8 files changed