drm/exynos: dsi: modify a error type when getting a node failed

This patch makes it to return -EINVAL instead of -ENXIO
when getting a port or remote node failed.
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>

drivers/gpu/drm/exynos/exynos_drm_dsi.c

@@ -1735,13 +1735,13 @@ static int exynos_dsi_parse_dt(struct exynos_dsi *dsi)
 
 	ep = of_graph_get_next_endpoint(node, NULL);
 	if (!ep) {
-		ret = -ENXIO;
+		ret = -EINVAL;
 		goto end;
 	}
 
 	dsi->bridge_node = of_graph_get_remote_port_parent(ep);
 	if (!dsi->bridge_node) {
-		ret = -ENXIO;
+		ret = -EINVAL;
 		goto end;
 	}
 end: