display: Defers Power On/Off request in case of pending CWB Teardown

Defers Power On/Off request in case of pending CWB Teardown to avoid
deadlock scenario in case of suspend request immediately after refresh.
Additionally removes WaitForCommitDoneAsync calls to address additional
deadlock scenarios.

Change-Id: Ifae709277c3f0e50c9c0c64bc2727434dc9e3137
7 files changed