ASoC: SAMSUNG: Fix build error

This patch adds <linux/modules.h> to fix following build errors.

sound/soc/codecs/wm8994.c: In function 'wm8994_readable':
sound/soc/codecs/wm8994.c:58: warning: unused variable 'wm8994' sound/soc/samsung/smdk_wm8994.c:176: error: expected declaration specifiers or '...' before string constant sound/soc/samsung/smdk_wm8994.c:176: warning: data definition has no type or storage class sound/soc/samsung/smdk_wm8994.c:176: warning: type defaults to 'int' in declaration of 'MODULE_DESCRIPTION' sound/soc/samsung/smdk_wm8994.c:176: warning: function declaration isn't a prototype sound/soc/samsung/smdk_wm8994.c:177: error: expected declaration specifiers or '...' before string constant

---
 sound/soc/samsung/smdk_wm8994.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index f75e439..ad9ac42 100644
@@ -9,6 +9,7 @@
 
 #include "../codecs/wm8994.h"
 #include <sound/pcm_params.h>
+#include <linux/module.h>
 
  /*
   * Default CFG switch settings to use this driver:

1.7.1

Applied, thanks.