ALSA: hda - enable SPDIF output for Intel DX58SO board

ALC889 has two SPDIF outputs: 0x06, 0x10. Board vendors can use either or both.
DX58SO uses 0x10, but the driver assumes 0x06. The safe solution is to add
0x10 as slave output to the existing 0x06.

Reported-by: Jeroen Van Breedam <jeroen.vanbreedam@sgr5.be>
Tested-by: Jeroen Van Breedam <jeroen.vanbreedam@sgr5.be>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
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 8209779..f35e58a 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -8764,6 +8764,10 @@
 	{}
 };
 
+static hda_nid_t alc883_slave_dig_outs[] = {
+	ALC1200_DIGOUT_NID, 0,
+};
+
 static hda_nid_t alc1200_slave_dig_outs[] = {
 	ALC883_DIGOUT_NID, 0,
 };
@@ -8809,6 +8813,7 @@
 		.dac_nids = alc883_dac_nids,
 		.dig_out_nid = ALC883_DIGOUT_NID,
 		.dig_in_nid = ALC883_DIGIN_NID,
+		.slave_dig_outs = alc883_slave_dig_outs,
 		.num_channel_mode = ARRAY_SIZE(alc883_3ST_6ch_intel_modes),
 		.channel_mode = alc883_3ST_6ch_intel_modes,
 		.need_dac_fix = 1,