[ALSA] Remove xxx_t typedefs: OPL4

Modules: OPL4

Remove xxx_t typedefs from the OPL4 driver

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/opl4.h b/include/sound/opl4.h
index 20c0442..60ae845 100644
--- a/include/sound/opl4.h
+++ b/include/sound/opl4.h
@@ -22,11 +22,11 @@
 
 #include <sound/opl3.h>
 
-typedef struct opl4 opl4_t;
+struct snd_opl4;
 
-extern int snd_opl4_create(snd_card_t *card,
+extern int snd_opl4_create(struct snd_card *card,
 			   unsigned long fm_port, unsigned long pcm_port,
 			   int seq_device,
-			   opl3_t **opl3, opl4_t **opl4);
+			   struct snd_opl3 **opl3, struct snd_opl4 **opl4);
 
 #endif /* __SOUND_OPL4_H */