Ensure that any queued events are issued when disabling the crtc. This
avoids timeouts when we come back and wait for dependencies (like the
previous frame's flip_done).

Changes in v2:
- None
Changes in v3:
- Rebased on Archit's private_obj set
Changes in v4:
- None
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>