decode device IDs from parameters

def cmd_devid(self, args):
        '''decode device IDs from parameters'''
        for p in self.mav_param.keys():
            if p.startswith('COMPASS_DEV_ID'):
                mp_util.decode_devid(self.mav_param[p], p)
            if p.startswith('INS_') and p.endswith('_ID'):
                mp_util.decode_devid(self.mav_param[p], p)