Input: misc - use macro module_platform_driver()

Commit 940ab88962bc1aff3273a8356d64577a6e386736 introduced a new macro to
save some platform_driver boilerplate code. Use it.

Signed-off-by: JJ Ding <dgdunix@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/misc/wm831x-on.c b/drivers/input/misc/wm831x-on.c
index c3d7ba5..47f18d6 100644
--- a/drivers/input/misc/wm831x-on.c
+++ b/drivers/input/misc/wm831x-on.c
@@ -145,18 +145,7 @@
 		.owner	= THIS_MODULE,
 	},
 };
-
-static int __init wm831x_on_init(void)
-{
-	return platform_driver_register(&wm831x_on_driver);
-}
-module_init(wm831x_on_init);
-
-static void __exit wm831x_on_exit(void)
-{
-	platform_driver_unregister(&wm831x_on_driver);
-}
-module_exit(wm831x_on_exit);
+module_platform_driver(wm831x_on_driver);
 
 MODULE_ALIAS("platform:wm831x-on");
 MODULE_DESCRIPTION("WM831x ON pin");