ASoC: Flag AD1980 as an AC97 interface

Special handling is required for suspend and resume of AC97 codecs
due to the control path going over the data bus.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/ad1980.c b/sound/soc/codecs/ad1980.c
index 1a3ea05..a9a2681 100644
--- a/sound/soc/codecs/ad1980.c
+++ b/sound/soc/codecs/ad1980.c
@@ -145,6 +145,7 @@
 
 struct snd_soc_dai ad1980_dai = {
 	.name = "AC97",
+	.ac97_control = 1,
 	.playback = {
 		.stream_name = "Playback",
 		.channels_min = 2,