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/ac97.c b/sound/soc/codecs/ac97.c
index 8f32167..221ec29f 100644
--- a/sound/soc/codecs/ac97.c
+++ b/sound/soc/codecs/ac97.c
@@ -148,17 +148,7 @@
 	.remove = __devexit_p(ac97_remove),
 };
 
-static int __init ac97_init(void)
-{
-	return platform_driver_register(&ac97_codec_driver);
-}
-module_init(ac97_init);
-
-static void __exit ac97_exit(void)
-{
-	platform_driver_unregister(&ac97_codec_driver);
-}
-module_exit(ac97_exit);
+module_platform_driver(ac97_codec_driver);
 
 MODULE_DESCRIPTION("Soc Generic AC97 driver");
 MODULE_AUTHOR("Liam Girdwood");