drm/amd/display: Add monitor patch for backlight off

[Why]
Different panel need different time from backlight disable to end of valid video data,
if the time is too short, panel will flash when dpms off

[How]
Add monitor patch to control the time from backlight disable to end of valid video data,
Signed-off-by: Xiaodong Yan <Xiaodong.Yan@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c

@@ -119,6 +119,10 @@ bool edp_receiver_ready_T9(struct dc_link *link)
 			break;
 		udelay(100); //MAx T9
 	} while (++tries < 50);
+
+	if (link->local_sink->edid_caps.panel_patch.extra_delay_backlight_off > 0)
+		udelay(link->local_sink->edid_caps.panel_patch.extra_delay_backlight_off * 1000);
+
 	return result;
 }
 bool edp_receiver_ready_T7(struct dc_link *link)

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

@@ -201,6 +201,7 @@ union display_content_support {
 struct dc_panel_patch {
 	unsigned int dppowerup_delay;
 	unsigned int extra_t12_ms;
+	unsigned int extra_delay_backlight_off;
 };
 
 struct dc_edid_caps {