sound: virtuoso: enable UART on Xonar HDAV1.3

This hardware has a better chance of working correctly if we don't
forget to enable it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/oxygen/virtuoso.c

@@ -908,6 +908,7 @@ static const struct oxygen_model model_xonar_hdav = {
 	.dac_channels = 8,
 	.dac_volume_min = 0x0f,
 	.dac_volume_max = 0xff,
+	.misc_flags = OXYGEN_MISC_MIDI,
 	.function_flags = OXYGEN_FUNCTION_2WIRE,
 	.dac_i2s_format = OXYGEN_I2S_FORMAT_LJUST,
 	.adc_i2s_format = OXYGEN_I2S_FORMAT_LJUST,