The MTA will finally add elevators to the 125th St 1 train station, making the elevated structure accessible to wheelchair users under the Americans with Disabilities Act (ADA), agency officials announced on Friday. The transit authority will install one elevator between the street and the station's mezzanine level and another two between the mezzanine and northbound and southbound platforms, MTA Chair and CEO Janno Lieber said during a May 8 ne…