ASoC: Convert CODEC drivers to module_platform_driver

Factors out a bit of boilerplate.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/ad73311.c b/sound/soc/codecs/ad73311.c
index 8d793e9..ee7a68d 100644
--- a/sound/soc/codecs/ad73311.c
+++ b/sound/soc/codecs/ad73311.c
@@ -63,17 +63,7 @@
 	.remove = __devexit_p(ad73311_remove),
 };
 
-static int __init ad73311_init(void)
-{
-	return platform_driver_register(&ad73311_codec_driver);
-}
-module_init(ad73311_init);
-
-static void __exit ad73311_exit(void)
-{
-	platform_driver_unregister(&ad73311_codec_driver);
-}
-module_exit(ad73311_exit);
+module_platform_driver(ad73311_codec_driver);
 
 MODULE_DESCRIPTION("ASoC ad73311 driver");
 MODULE_AUTHOR("Cliff Cai ");