msm_fb: Wifi display changes for commit ioctl

This change handles panel updates for WFD panel via
overlay_commit interface, along with conglomeration of
some common code across pan_update and overlay_commit ioctls

Change-Id: I092180a4f2be801cd5b9008e99d0b712d089746b
Signed-off-by: Kalyan Thota <kalyant@codeaurora.org>