SPM: TFTF test of FFA_VERSION interface

Implemented test to FFA_VERSION interface:
- "test_ffa_version.c" contains functions to test FFA_VERSION ABI;
- Test suite for FFA_VERSION ABI in tests-spm.xml;
- Helper macros changed in "ffa_helpers.h".

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I6b0e937e30fceaa21a57c4ba0761a62049b16c0d
7 files changed