ALSA: hda - VIA: Fix Smart5.1 isn't useful for 6 audio jacks motherboard.

For some motherboards with 5 or 6 audio jacks which had six or eight multiple
channels output, smart5.1 item is no useful and should be removed.

Signed-off-by: Lydia Wang <lydiawang@viatech.com.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_via.c

@@ -1021,6 +1021,11 @@ static int via_smart51_build(struct via_spec *spec)
 	hda_nid_t nid;
 	int i;
 
+	if (!cfg)
+		return 0;
+	if (cfg->line_outs > 2)
+		return 0;
+
 	knew = via_clone_control(spec, &via_smart51_mixer[0]);
 	if (knew == NULL)
 		return -ENOMEM;