[ALSA] oxygen: generalize DAC volume TLV handling

Add a pointer for DAC volume TLV data to the model structure so that the
model driver do not need to manually assign it in their control filter.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/oxygen/oxygen_mixer.c b/sound/pci/oxygen/oxygen_mixer.c
index 056581e..cc0cdda 100644
--- a/sound/pci/oxygen/oxygen_mixer.c
+++ b/sound/pci/oxygen/oxygen_mixer.c
@@ -941,6 +941,11 @@
 			return err;
 		if (err == 1)
 			continue;
+		if (!strcmp(template.name, "Master Playback Volume") &&
+		    chip->model->dac_tlv) {
+			template.tlv.p = chip->model->dac_tlv;
+			template.access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
+		}
 		ctl = snd_ctl_new1(&template, chip);
 		if (!ctl)
 			return -ENOMEM;