linux-imx

drm/radeon: hook up backlight functions for CI and KV family.

Fixes crashes when handling atif events due to the lack of a
callback being registered.

Signed-off-by: Samuel Li <samuel.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org