ALSA: convert sound/* to use module_platform_driver()

This patch converts the drivers in sound/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/ml403-ac97cr.c b/sound/drivers/ml403-ac97cr.c
index 2ee82c5..07ede97 100644
--- a/sound/drivers/ml403-ac97cr.c
+++ b/sound/drivers/ml403-ac97cr.c
@@ -1341,15 +1341,4 @@
 	},
 };
 
-static int __init alsa_card_ml403_ac97cr_init(void)
-{
-	return platform_driver_register(&snd_ml403_ac97cr_driver);
-}
-
-static void __exit alsa_card_ml403_ac97cr_exit(void)
-{
-	platform_driver_unregister(&snd_ml403_ac97cr_driver);
-}
-
-module_init(alsa_card_ml403_ac97cr_init)
-module_exit(alsa_card_ml403_ac97cr_exit)
+module_platform_driver(snd_ml403_ac97cr_driver);