drm/amd/display: Set DPIA link endpoint type

[why & how]
We will need a way to distinguish physically connected
links and DPIA endpoints.
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1732,6 +1732,8 @@ static bool dc_link_construct_dpia(struct dc_link *link,
 		  init_params->connector_index,
 		  link->connector_signal);
 
+	link->ep_type = DISPLAY_ENDPOINT_USB4_DPIA;
+
 	/* TODO: Initialize link : funcs->link_init */
 
 	ddc_service_init_data.ctx = link->ctx;

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

@@ -955,6 +955,7 @@ enum dc_psr_version {
 /* Possible values of display_endpoint_id.endpoint */
 enum display_endpoint_type {
 	DISPLAY_ENDPOINT_PHY = 0, /* Physical connector. */
+	DISPLAY_ENDPOINT_USB4_DPIA, /* USB4 DisplayPort tunnel. */
 	DISPLAY_ENDPOINT_UNKNOWN = -1
 };