ALSA: use subsys_initcall for sound core instead of module_init

This is needed for built-in drivers which are built before the sound directory,
like thinkpad_acpi.

Otherwise, registering a card fails.

Signed-off-by: Thadeu Lima de Souza Cascardo <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/core/sound.c

···
 	unregister_chrdev(major, "alsa");
 }
 
-module_init(alsa_sound_init)
-module_exit(alsa_sound_exit)
+subsys_initcall(alsa_sound_init);
+module_exit(alsa_sound_exit);

sound/sound_core.c

···
 	class_destroy(sound_class);
 }
 
-module_init(init_soundcore);
+subsys_initcall(init_soundcore);
 module_exit(cleanup_soundcore);