drm/amd/display: register edp_backlight_control() for DCN301

As made mention of in commit 099303e ("drm/amd/display: eDP
intermittent black screen during PnP"), we need to turn off the
display's backlight before powering off an eDP display. Not doing so
will result in undefined behaviour according to the eDP spec. So, set
DCN301's edp_backlight_control() function pointer to
dce110_edp_backlight_control().

Cc: [email protected]
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2765
Fixes: 9c75891 ("drm/amd/display: rework recent update PHY state commit")
Suggested-by: Swapnil Patel <[email protected]>
Reviewed-by: Harry Wentland <[email protected]>
Signed-off-by: Hamza Mahfooz <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: effective-light

drivers/gpu/drm/amd/display/dc/dcn301/dcn301_init.c

@@ -75,6 +75,7 @@ static const struct hw_sequencer_funcs dcn301_funcs = {
 	.get_hw_state = dcn10_get_hw_state,
 	.clear_status_bits = dcn10_clear_status_bits,
 	.wait_for_mpcc_disconnect = dcn10_wait_for_mpcc_disconnect,
+	.edp_backlight_control = dce110_edp_backlight_control,
 	.edp_power_control = dce110_edp_power_control,
 	.edp_wait_for_hpd_ready = dce110_edp_wait_for_hpd_ready,
 	.set_cursor_position = dcn10_set_cursor_position,