fix(spmd): perform G0 interrupt acknowledge and deactivation

Prior to delegating handling of Group0 secure interrupt to platform
handler, SPMD framework must acknowledge the highest pending interrupt.
Moreover, once the platform has handled the interrupt successfully,
SPMD must deactivate the interrupt.

The rationale behind this decision is SPMD framework is well suited to
perform interrupt management at GIC boundary while the platform handler
is well equipped to deal with the device interface related to the
interrupt.

This patch also fixes a bug in the error code returned upon invocation
of FFA_EL3_INTR_HANDLE from normal world.

Change-Id: If8fef51899e25f966038cc01ec58c84ee25e88eb
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
2 files changed