ALSA: hda - Add standard channel maps

Although HD-audio allows pair-wise channel configurations, only the
fixed channel positions are used in this version.  In future, this can
be changed and allow user to modify the channel positions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 6134999..1907dda 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -2287,6 +2287,8 @@
 			p = &alc_pcm_analog_playback;
 		info->stream[SNDRV_PCM_STREAM_PLAYBACK] = *p;
 		info->stream[SNDRV_PCM_STREAM_PLAYBACK].nid = spec->multiout.dac_nids[0];
+		info->stream[SNDRV_PCM_STREAM_PLAYBACK].channels_max =
+			spec->multiout.max_channels;
 	}
 	if (spec->adc_nids) {
 		p = spec->stream_analog_capture;