ALSA: Simplify snd_device_register() variants

Now that all callers have been replaced with
snd_device_register_for_dev(), let's drop the obsolete device
registration code and concentrate only on the code handling struct
device directly.  That said,

- remove the old snd_device_register(),
- rename snd_device_register_for_dev() with snd_device_register(),
- drop superfluous arguments from snd_device_register(),
- change snd_unregister_device() to pass the device pointer directly

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/timer.c b/sound/core/timer.c
index dae40ac..9f0c703 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1976,9 +1976,8 @@
 		return err;
 	}
 
-	err = snd_register_device_for_dev(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
-					  &snd_timer_f_ops, NULL,
-					  &timer_dev, NULL, NULL);
+	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
+				  &snd_timer_f_ops, NULL, &timer_dev);
 	if (err < 0) {
 		pr_err("ALSA: unable to register timer device (%i)\n", err);
 		snd_timer_free_all();
@@ -1992,7 +1991,7 @@
 
 static void __exit alsa_timer_exit(void)
 {
-	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
+	snd_unregister_device(&timer_dev);
 	snd_timer_free_all();
 	put_device(&timer_dev);
 	snd_timer_proc_done();