headers_check fix: sound/hdsp.h

fix the following 'make headers_check' warning:

  usr/include/sound/hdsp.h:33: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/sound/hdsp.h

@@ -19,6 +19,8 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/types.h>
+
 #define HDSP_MATRIX_MIXER_SIZE 2048
 
 enum HDSP_IO_Type {