sdm: Call Asynchronous NULL Commit in Power Mode APIs

Synchronous NULL Commit holds the Modeset Lock in DRM driver, which
can block the Commits happening on other display(s) in the system.
DAL will wait on Release/Retire fence to make sure that H/W Power
transition gets completed in SetPowerMode call from SurfaceFlinger.

Change-Id: I839035853e73b35ce3a998b74be442ef0923ee60
CRs-Fixed: 2449460
1 file changed