drm/amd/display: Use pwrseq instance to determine eDP instance

[Why & How]
Link index doesn't always correspond to the appropriate eDP instance.
We can assume lower link index is a lower eDP instance and set panel
control instance accordingly.
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NJake Wang <haonan.wang2@amd.com>
Reviewed-by: NNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: NQingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -1383,6 +1383,8 @@ static bool dc_link_construct(struct dc_link *link,
 	struct dc_bios *bios = init_params->dc->ctx->dc_bios;
 	const struct dc_vbios_funcs *bp_funcs = bios->funcs;
 	struct bp_disp_connector_caps_info disp_connect_caps_info = { 0 };
+	struct dc_link *edp_links[MAX_NUM_EDP];
+	int edp_num;
 
 	DC_LOGGER_INIT(dc_ctx->logger);
 
@@ -1506,7 +1508,11 @@ static bool dc_link_construct(struct dc_link *link,
 		(link->link_id.id == CONNECTOR_ID_EDP ||
 			link->link_id.id == CONNECTOR_ID_LVDS)) {
 		panel_cntl_init_data.ctx = dc_ctx;
-		panel_cntl_init_data.inst = link->link_index;
+		get_edp_links(panel_cntl_init_data.ctx->dc, edp_links, &edp_num);
+		if ((edp_num > 1) && (link->link_index > edp_links[0]->link_index))
+			panel_cntl_init_data.inst = 1;
+		else
+			panel_cntl_init_data.inst = 0;
 		link->panel_cntl =
 			link->dc->res_pool->funcs->panel_cntl_create(
 								&panel_cntl_init_data);