Backmerge drm-next because the conflict between Ander's atomic fixes
for 4.2 and Maartens future work are getting to unwielding to handle.

Conflicts:
	drivers/gpu/drm/i915/intel_display.c
	drivers/gpu/drm/i915/intel_ringbuffer.h

Just always take ours, same as git merge -X ours, but done by hand
because I didn't trust git: It's confusing that it doesn't show any
conflicts in the merge diff at all.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>