[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>

sound/pci/oxygen/oxygen_pcm.c

@@ -714,7 +714,7 @@ int __devinit oxygen_pcm_init(struct oxygen *chip)
 					      snd_dma_pci_data(chip->pci),
 					      128 * 1024, 256 * 1024);
 
-	if (chip->has_2nd_ac97_codec) {
+	if (chip->has_ac97_1) {
 		err = snd_pcm_new(chip->card, "AC97", 2, 1, 0, &pcm);
 		if (err < 0)
 			return err;