ASoC: fix compile breakage - add a missing header include

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc-dai.h

@@ -16,6 +16,8 @@
 
 #include <linux/list.h>
 
+#include <sound/soc.h>
+
 struct snd_pcm_substream;
 
 /*