msm: smsm: Add SMSM notifier wakelock

Add wakelock that is locked in the SMSM interrupt handler and unlocked
in the workqueue after notifications have been completed.

This prevents the sleep code from putting the system to sleep before the
SMSM notification workqueue gets scheduled.

CRs-Fixed: 345581
Change-Id: Idb93493dfa79cd4ea80b857ed92c4b2f9b96af3f
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>