text: If we tag the atm with the fee its complicated.
  In case of a stand-alone atm it would be fee=some.
  For an atm as part of a bank it is not defined so far. In Great Britain sometimes atm:fee=yes/no/ etc is used.
  (see https://taginfo.openstreetmap.org/keys/atm%3Afee#values)
  atm:fee=some would make sense to me, even if it is new.
  