updated revision.txt for serial/serial5 remapping
updated revision.txt for serial/serial5 remapping

stevemarple/Arduino-org,stevemarple/Arduino-org,arduino-org/Arduino,arduino-org/Arduino,arduino-org/Arduino,stevemarple/Arduino-org,stevemarple/Arduino-org,arduino-org/Arduino,arduino-org/Arduino,arduino-org/Arduino,arduino-org/Arduino,stevemarple/Arduino-org,stevemarple/Arduino-org,stevemarple/Arduino-org,arduino-org/Arduino,stevemarple/Arduino-org