drm/msm/sde: trigger async inline rotation before frame done

Trigger the kickoff for ASYNC inline rotation before waiting
for the previous frame's ping pong done in command mode. This
provides the hardware with a larger window in which to start
the rotation for the current frame.

Change-Id: Iaacd14f725d3d1b87e1a2e08bc5a9784764e3562
Signed-off-by: Clarence Ip <cip@codeaurora.org>