ALSA: hda - AD1988 codec - fix SPDIF-input mixer initialization (unmute)

The SPDIF-input pin 0x1c is muted by default in hardware. Unmute appropriate
pin to get captured samples instead zeros. Tested on Lenovo Thinkstation.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/hda/patch_analog.c

@@ -2458,6 +2458,12 @@ static struct hda_verb ad1988_spdif_init_verbs[] = {
 	{ }
 };
 
+static struct hda_verb ad1988_spdif_in_init_verbs[] = {
+	/* unmute SPDIF input pin */
+	{0x1c, AC_VERB_SET_AMP_GAIN_MUTE, AMP_IN_UNMUTE(0)},
+	{ }
+};
+
 /* AD1989 has no ADC -> SPDIF route */
 static struct hda_verb ad1989_spdif_init_verbs[] = {
 	/* SPDIF-1 out pin */
@@ -3193,8 +3199,11 @@ static int patch_ad1988(struct hda_codec *codec)
 				ad1988_spdif_init_verbs;
 		}
 	}
-	if (spec->dig_in_nid && codec->vendor_id < 0x11d4989a)
+	if (spec->dig_in_nid && codec->vendor_id < 0x11d4989a) {
 		spec->mixers[spec->num_mixers++] = ad1988_spdif_in_mixers;
+		spec->init_verbs[spec->num_init_verbs++] =
+			ad1988_spdif_in_init_verbs;
+	}
 
 	codec->patch_ops = ad198x_patch_ops;
 	switch (board_config) {