drm/vc4: use platform_register_drivers

Use platform_register_drivers instead of open coding the iteration over
component platform drivers in the vc4_drv module.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170317170059.17821-1-p.zabel@pengutronix.de

drivers/gpu/drm/vc4/vc4_drv.c

@@ -349,26 +349,20 @@ static struct platform_driver vc4_platform_driver = {
 
 static int __init vc4_drm_register(void)
 {
-	int i, ret;
+	int ret;
+
+	ret = platform_register_drivers(component_drivers,
+					ARRAY_SIZE(component_drivers));
+	if (ret)
+		return ret;
 
-	for (i = 0; i < ARRAY_SIZE(component_drivers); i++) {
-		ret = platform_driver_register(component_drivers[i]);
-		if (ret) {
-			while (--i >= 0)
-				platform_driver_unregister(component_drivers[i]);
-			return ret;
-		}
-	}
 	return platform_driver_register(&vc4_platform_driver);
 }
 
 static void __exit vc4_drm_unregister(void)
 {
-	int i;
-
-	for (i = ARRAY_SIZE(component_drivers) - 1; i >= 0; i--)
-		platform_driver_unregister(component_drivers[i]);
-
+	platform_unregister_drivers(component_drivers,
+				    ARRAY_SIZE(component_drivers));
 	platform_driver_unregister(&vc4_platform_driver);
 }