usb: common: otg-fsm: add license to usb-otg-fsm

Fix warning about tainted kernel because usb-otg-fsm has no license.
WARNING: with this patch usb-otg-fsm module can be loaded
but then the kernel will hang. Tested with a udoo quad board.

Cc: <stable@vger.kernel.org> #v4.1+
Signed-off-by: Oscar <oscar@naiandei.net>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/common/usb-otg-fsm.c

@@ -21,6 +21,7 @@
  * 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/mutex.h>
@@ -450,3 +451,4 @@ int otg_statemachine(struct otg_fsm *fsm)
 	return fsm->state_changed;
 }
 EXPORT_SYMBOL_GPL(otg_statemachine);
+MODULE_LICENSE("GPL");