ALSA: Add missing include of pcm.h to pcm_params.h

There's a dependency but no #include.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/pcm_params.h b/include/sound/pcm_params.h
index f494f1e..37ae12e 100644
--- a/include/sound/pcm_params.h
+++ b/include/sound/pcm_params.h
@@ -22,6 +22,8 @@
  *
  */
 
+#include <sound/pcm.h>
+
 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, 
 			   struct snd_pcm_hw_params *params,
 			   snd_pcm_hw_param_t var, int *dir);