drm: use for_each_endpoint_of_node macro in drm_of_find_possible_crtcs

Using the for_each_... macro should make the code a bit shorter and
easier to read.

Signed-off-by: Philipp Zabel <[e-mail]>
Acked-by: Laurent Pinchart <[e-mail]>

drivers/gpu/drm/drm_of.c

···
 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 				    struct device_node *port)
 {
-	struct device_node *remote_port, *ep = NULL;
+	struct device_node *remote_port, *ep;
 	uint32_t possible_crtcs = 0;
 
-	do {
-		ep = of_graph_get_next_endpoint(port, ep);
-		if (!ep)
-			break;
-
+	for_each_endpoint_of_node(port, ep) {
 		remote_port = of_graph_get_remote_port(ep);
 		if (!remote_port) {
 			of_node_put(ep);
···
 		possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
 
 		of_node_put(remote_port);
-	} while (1);
+	}
 
 	return possible_crtcs;
 }