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/cx20442.c b/sound/soc/codecs/cx20442.c
index bc7067d..ae55e31 100644
--- a/sound/soc/codecs/cx20442.c
+++ b/sound/soc/codecs/cx20442.c
@@ -391,17 +391,7 @@
 	.remove = __exit_p(cx20442_platform_remove),
 };
 
-static int __init cx20442_init(void)
-{
-	return platform_driver_register(&cx20442_platform_driver);
-}
-module_init(cx20442_init);
-
-static void __exit cx20442_exit(void)
-{
-	platform_driver_unregister(&cx20442_platform_driver);
-}
-module_exit(cx20442_exit);
+module_platform_driver(cx20442_platform_driver);
 
 MODULE_DESCRIPTION("ASoC CX20442-11 voice modem codec driver");
 MODULE_AUTHOR("Janusz Krzysztofik");