fix(rmmd): return X4 output value

Return values contained in 'smc_result' structure
are shifted down by one register:
X1 written by RMM is returned to NS in X0 and
X5 is returned in X4.

Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
Change-Id: I92907ac3ff3bac8554643ae7c198a4a758c38cb3
2 files changed