gpu: host1x: Use platform_register/unregister_drivers()

These new helpers simplify implementing multi-driver modules and
properly handle failure to register one driver by unregistering all
previously registered drivers.
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/gpu/host1x/dev.c

@@ -212,6 +212,11 @@ static struct platform_driver tegra_host1x_driver = {
 	.remove = host1x_remove,
 };
 
+static struct platform_driver * const drivers[] = {
+	&tegra_host1x_driver,
+	&tegra_mipi_driver,
+};
+
 static int __init tegra_host1x_init(void)
 {
 	int err;
@@ -220,28 +225,17 @@ static int __init tegra_host1x_init(void)
 	if (err < 0)
 		return err;
 
-	err = platform_driver_register(&tegra_host1x_driver);
-	if (err < 0)
-		goto unregister_bus;
-
-	err = platform_driver_register(&tegra_mipi_driver);
+	err = platform_register_drivers(drivers, ARRAY_SIZE(drivers));
 	if (err < 0)
-		goto unregister_host1x;
+		bus_unregister(&host1x_bus_type);
 
-	return 0;
-
-unregister_host1x:
-	platform_driver_unregister(&tegra_host1x_driver);
-unregister_bus:
-	bus_unregister(&host1x_bus_type);
 	return err;
 }
 module_init(tegra_host1x_init);
 
 static void __exit tegra_host1x_exit(void)
 {
-	platform_driver_unregister(&tegra_mipi_driver);
-	platform_driver_unregister(&tegra_host1x_driver);
+	platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
 	bus_unregister(&host1x_bus_type);
 }
 module_exit(tegra_host1x_exit);