Merge tag 'imx-drm-next-2019-02-22' of git://git.pengutronix.de/pza/linux into drm-next

drm/imx: handle pending updates better, add plane zpos property support

- Add a mechanism to only send commit done events once all pending
  updates have been applied. This closes a small race window where
  already armed events could fire even though the double buffered
  hardware update just missed the update window.
- Add plane zpos property support to allow placing the overlay plane
  behind the primary plane.
- Allow building imx-drm on all platforms under COMPILE_TEST.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Philipp Zabel <pza@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190222112350.m3ucezilqx6cyest@pengutronix.de