drm/omap: simplify omap_display_id

We no longer need to check for the DSS API, since all encoders,
panels and connectors have been converted to the bridge API.
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215104657.802264-44-tomi.valkeinen@ti.com

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -206,14 +206,7 @@ static int omap_display_id(struct omap_dss_device *output)
 {
 	struct device_node *node = NULL;
 
-	if (output->next) {
-		struct omap_dss_device *display = output;
-
-		while (display->next)
-			display = display->next;
-
-		node = display->dev->of_node;
-	} else if (output->bridge) {
+	if (output->bridge) {
 		struct drm_bridge *bridge = output->bridge;
 
 		while (drm_bridge_get_next_bridge(bridge))