drm/amd/display: Fix passive dongle mistaken as active dongle in EDID emulation

[Why]
dongle_type is set during dongle connection but for passive dongles,
dongle_type is not set. If user starts with an active dongle and
then switches to a passive dongle, it will still report as an active
dongle. Trying to emulate the wrong connecter type results in display
not lighting up.

[How]
Set dpcd_caps.dongle_type for passive dongles in detect_dp().
Signed-off-by: NSamson Tam <Samson.Tam@amd.com>
Reviewed-by: NJoshua Aberback <Joshua.Aberback@amd.com>
Acked-by: NEryk Brol <eryk.brol@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -763,6 +763,7 @@ static bool detect_dp(struct dc_link *link,
 		sink_caps->signal = dp_passive_dongle_detection(link->ddc,
 								sink_caps,
 								audio_support);
+		link->dpcd_caps.dongle_type = sink_caps->dongle_type;
 	}
 
 	return true;