musb: fix warning in include/linux/usb/musb.h

Fix the following build warning by including linux/compat.h:
include/linux/usb/musb.h:110: warning: 'struct device' declared inside
parameter list
include/linux/usb/musb.h:110: warning: its scope is only this definition
or declaration, which is probably not what you want

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>

include/linux/usb/musb.h

@@ -14,6 +14,8 @@
 #define __deprecated
 #endif
 
+#include <linux/compat.h>
+
 /* The USB role is defined by the connector used on the board, so long as
  * standards are being followed.  (Developer boards sometimes won't.)
  */