disp: msm: sde: add one-shot qsync mode support

Add support to enable one-shot mode during qsync
update. This feature ensures the frame drops can be
reduced due to delayed software flush for the
current commit. Also, add changes to disable the qsync
feature post commit.

Change-Id: Icb158853f52284bcf8fa641e5f62200c5460b660
Signed-off-by: Kalyan Thota <kalyant@codeaurora.org>
Signed-off-by: Jayaprakash <jmadiset@codeaurora.org>