Merge pull request #7011 from thinkyhead/bf_serial_macros

Marlin/G26_Mesh_Validation_Tool.cpp

Marlin/I2CPositionEncoder.cpp

Marlin/M100_Free_Mem_Chk.cpp

Marlin/Marlin_main.cpp

Marlin/cardreader.cpp

Marlin/configuration_store.cpp

Marlin/endstops.cpp

Marlin/gcode.cpp

Marlin/gcode.h

Marlin/language_en.h

Marlin/pinsDebug.h

Marlin/planner.cpp

Marlin/printcounter.cpp

Marlin/serial.h

Marlin/stepper.cpp

Marlin/stepper.h

Marlin/stepper_dac.cpp

Marlin/temperature.cpp

Marlin/twibus.cpp

Marlin/ubl.cpp