control gimbal mode

def cmd_gimbal_mode(self, args):
        '''control gimbal mode'''
        if len(args) != 1:
            print("usage: gimbal mode <GPS|MAVLink>")
            return
        if args[0].upper() == 'GPS':
            mode = mavutil.mavlink.MAV_MOUNT_MODE_GPS_POINT
        elif args[0].upper() == 'MAVLINK':
            mode = mavutil.mavlink.MAV_MOUNT_MODE_MAVLINK_TARGETING
        elif args[0].upper() == 'RC':
            mode = mavutil.mavlink.MAV_MOUNT_MODE_RC_TARGETING
        else:
            print("Unsupported mode %s" % args[0])
        self.master.mav.mount_configure_send(self.target_system,
                                             self.target_component,
                                             mode,
                                             1, 1, 1)