drm/amd/display: power down eDP if eDP not present

[Why]
When init, driver will power up eDP to check eDP
present or not. If eDP not present, driver doesn't
power off eDP VDD cause power consumption.

[How]
If eDP is not present when detection, power off eDP
VDD.
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Paul Hsieh <Paul.Hsieh@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/link/link_detection.c

@@ -1227,6 +1227,11 @@ bool link_detect_connection_type(struct dc_link *link, enum dc_connection_type *
 		/* TODO: need to do the actual detection */
 	} else {
 		*type = dc_connection_none;
+		if (link->connector_signal == SIGNAL_TYPE_EDP) {
+			/* eDP is not connected, power down it */
+			if (!link->dc->config.edp_no_power_sequencing)
+				link->dc->hwss.edp_power_control(link, false);
+		}
 	}
 
 	return true;