sdm: Handle idle fall back and idle power collapse with same event

Driver uses same event to trigger idle fall back on video mode panels
and idle power collapse on command mode panels. Handle both with same
event at HAL event handler.

Skip validate should be reset during idle power collapse event.

CRs-Fixed: 2110497

Change-Id: Ie3a0195c4375aebd79e8c7daef7131579bceda9f
3 files changed