[ALSA] oxygen: make AC97 codec optional

Only initialize and create mixer controls for the first AC97 codec when
one has actually been detected.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/pci/oxygen/oxygen.h b/sound/pci/oxygen/oxygen.h
index 4a0c663..66dee95 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -56,7 +56,8 @@
 	u8 spdif_playback_enable;
 	u8 ak4396_reg1;
 	u8 revision;
-	u8 has_2nd_ac97_codec;
+	u8 has_ac97_0;
+	u8 has_ac97_1;
 	u32 spdif_bits;
 	u32 spdif_pcm_bits;
 	struct snd_pcm_substream *streams[PCM_COUNT];