drm/i915: use helpers

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --cc drivers/gpu/drm/i915/intel_display.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_overlay.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_sprite.c
Simple merge