[ALSA] ac97 - Fix vt1617a build ops

This patch connects the extra vt1616 controls for the vt1617a, which
is necessary to control the rear speakers on e.g. a Shuttle SN25P.
Signed-off-by: NDaniel Jacobowitz <drow@false.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

sound/pci/ac97/ac97_patch.c

@@ -3285,6 +3285,7 @@ int patch_vt1617a(struct snd_ac97 * ac97)
 	snd_ac97_write_cache(ac97, 0x5c, 0x20);
 	ac97->ext_id |= AC97_EI_SPDIF;	/* force the detection of spdif */
 	ac97->rates[AC97_RATES_SPDIF] = SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000;
+	ac97->build_ops = &patch_vt1616_ops;
 	return 0;
 }