SPM: Fix FLIH return to Privileged Thread mode

If a Privileged SPM code execution is interrupted
by FLIH interrupt, then on returning from the FLIH
handler restore Privileged Thread mode.

Change-Id: Ic9af7d6049971b8f1f1d1995cf9a5f2562470318
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
3 files changed