ASoC: Staticize ak4641_dai

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
diff --git a/sound/soc/codecs/ak4641.c b/sound/soc/codecs/ak4641.c
index ed96f247c..7a64e58 100644
--- a/sound/soc/codecs/ak4641.c
+++ b/sound/soc/codecs/ak4641.c
@@ -457,7 +457,7 @@
 	.set_sysclk   = ak4641_set_dai_sysclk,
 };
 
-struct snd_soc_dai_driver ak4641_dai[] = {
+static struct snd_soc_dai_driver ak4641_dai[] = {
 {
 	.name = "ak4641-hifi",
 	.id = 1,