fsa4480: Fix headset not detected during system suspend

Headset is not detected after system goes into suspend
as sufficient delay is not given after pm_stay_awake
for system to wakeup. Implementing freezable workqeueue
after pm_stay_awake resolves the issue.

Change-Id: Ia104a1577004a4242470f3b4150be23698fc92b1
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>