msm_fb: display: wfd with vsync driven frame push

To improve performance, hardware vsync event at mdp driver
is passed to framework so that both composition and frame
update are aligned at vsync event. This patch will upgrade
wfd to incorporate vsync driven frame push in consistence
with other interfaces.

Change-Id: If088826ec387446301f1f6acc311d909edb04163
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
(cherry picked from commit d74db5fcf24a223570137087aa5632593b315fcc)

Conflicts:

	drivers/video/msm/mdp4_overlay.c
	drivers/video/msm/mdp4_overlay_writeback.c

Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>