Makes csma default on econotag, redwire-io and cc2538
Makes csma default on econotag, redwire-io and cc2538

bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr