FF-A: Check FF-A return is a valid direct response

Added a helper function to check if return of FFA_MSG_SEND_DIRECT_REQ
is FFA_MSG_SEND_DIRECT_RESP.
This is intended to make it easier to maintain cactus test commands
framework.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Ia43e88908aa3cbdd529a8835bffe43dee3e04a76
5 files changed