Remove the old aarch64 tracker
    
    Per Peter Robinson in devel@, the ARMTracker should be used for both
    armv7hl and aarch64 build failures:
    
    https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/4OMGU5X2W4IHXSEYYJDLRGZRVSE5KDAV/
    
    Signed-off-by: Michel Alexandre Salim <salimma@fedoraproject.org>