mdp3: Wait for proper vsync when updating display frame

This fixes an issue where we would report that dma is displaying
new frame, but in fact were really still displaying the old
frame.

Change-Id: I99dc89b2341481ea42f9cce451b9b2833dd1f700
Signed-off-by: Terence Hampson <thampson@codeaurora.org>
4 files changed