Merge tag 'drm-fsl-dcu-for-v4.13' of http://git.agner.ch/git/linux-drm-fsl-dcu into drm-next

some fsl-dcu cleanups

* tag 'drm-fsl-dcu-for-v4.13' of http://git.agner.ch/git/linux-drm-fsl-dcu:
  drm/fsl-dcu: use new drm_atomic_helper_shutdown
  drm/fsl-dcu: implement irq_preinstall/uninstall callbacks
  drm/fsl: Drop drm_vblank_cleanup