In video playback through overlay, it is observed that, during
suspend/resume, genlock TIMEOUT errors are seen at the component
level.
drawLayerUsingOverlay() function locks buffers, but doesn't unlock
them, before going to suspend, making the genlock_lock_buffer calls
from video component to fail.
Unlock any overlay buffers before going to suspend.
CRs-fixed: 342878
(cherry picked from commit 4ffcd156710184fe492294fd55beea7d5f412116)
Change-Id: Id0165f370d05d9b4bdf71ddaea15cf00caa65896
3e189158c5