feat(ff-a): adding notifications SMC IDs

Defining SMC IDs for FF-A v1.1 notifications functionality, and adding
them to SPMD SMC handler, to ensure calls are forwarded to the SPMC.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Icc88aded0fd33507f7795e996bd4ff1c2fe679c8
2 files changed