Merge branch 'drm-fixes-4.3' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

regression fix for backlight on old laptops.

* 'drm-fixes-4.3' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: fix dpms when driver backlight control is disabled
  drm/radeon: move bl encoder assignment into bl init