Merge pull request #7723 from fiveangle/bf20-improve_avr_arch_detection

Marlin/src/HAL/HAL.h

Marlin/src/HAL/HAL_AVR/HAL_AVR.cpp

Marlin/src/HAL/HAL_AVR/HAL_AVR.h

Marlin/src/HAL/HAL_AVR/HAL_spi_AVR.cpp

Marlin/src/HAL/HAL_AVR/MarlinSerial.cpp

Marlin/src/HAL/HAL_AVR/persistent_store_impl.cpp

Marlin/src/HAL/HAL_AVR/servo_AVR.cpp

Marlin/src/HAL/HAL_AVR/watchdog_AVR.cpp

Marlin/src/HAL/HAL_DUE/persistent_store_impl.cpp

Marlin/src/HAL/HAL_SanityCheck.h

Marlin/src/HAL/HAL_endstop_interrupts.h

Marlin/src/HAL/HAL_pinsDebug.h

Marlin/src/HAL/HAL_spi_pins.h

Marlin/src/HAL/servo.h

Marlin/src/HAL/servo_private.h

Marlin/src/core/serial.h

Marlin/src/inc/MarlinConfig.h

Marlin/src/module/delta.cpp

Marlin/src/module/delta.h

Marlin/src/module/stepper.cpp