fix(ff-a): report FFA_YIELD support for SPs only

The FFA_YIELD interface is only valid at the virtual
FF-A instace, and not at the physical FF-A instance.
I.e. SPs can use the ABI with SMC conduit into the SPMC.
The NWd is not expected to call FFA_YIELD into SPMC.

This patch drops FFA_YIELD from the common test target
for FFA_FEATURES between tftf and cactus/ivy partitions,
adds the specific tests to both of them with expected
differences.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I7d9a5729b82f3f2f77631a8ab6210fa026078d7d
3 files changed