Revert "drm/amd/display: workaround for oled eDP not lighting up on DCN401"

This reverts commit e902dd7f.

A proper fix for this issue has been implemented in DMUB FW. So, no need
to keep the workaround.
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc.h

@@ -1045,7 +1045,6 @@ struct dc_debug_options {
 	unsigned int force_easf;
 	unsigned int force_sharpness;
 	unsigned int force_lls;
-	bool edp_oled_no_backlight_enable;
 };
 
 

drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c

@@ -248,9 +248,6 @@ bool edp_backlight_enable_aux(struct dc_link *link, bool enable)
 		link->connector_signal != SIGNAL_TYPE_DISPLAY_PORT))
 		return false;
 
-	if (link->dc->debug.edp_oled_no_backlight_enable && link->dpcd_sink_ext_caps.bits.oled)
-		return true;
-
 	if (core_link_write_dpcd(link, DP_SOURCE_BACKLIGHT_ENABLE,
 		&backlight_enable, 1) != DC_OK)
 		return false;

drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c

@@ -731,7 +731,6 @@ static const struct dc_debug_options debug_defaults_drv = {
 		}
 	},
 	.force_cositing = CHROMA_COSITING_TOPLEFT + 1,
-	.edp_oled_no_backlight_enable = true,
 };
 
 static struct dce_aux *dcn401_aux_engine_create(