Backmerge v4.9-rc8 to get at

commit e94bd173
Author: Michel Dänzer <michel.daenzer@amd.com>
Date:   Wed Nov 30 17:30:01 2016 +0900

drm: Don't call drm_for_each_crtc with a non-KMS driver

so I can apply Michel's follow-up patch.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>