powerpc/83xx/suspend: use builtin_platform_driver

Use builtin_platform_driver() helper to simplify the code.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NScott Wood <oss@buserror.net>

arch/powerpc/platforms/83xx/suspend.c

@@ -441,8 +441,4 @@ static struct platform_driver pmc_driver = {
 	.remove = pmc_remove
 };
 
-static int pmc_init(void)
-{
-	return platform_driver_register(&pmc_driver);
-}
-device_initcall(pmc_init);
+builtin_platform_driver(pmc_driver);