Merge pull request #7768 from thinkyhead/bf2_HAL_STM32F1

Marlin/src/HAL/HAL.h

Marlin/src/HAL/HAL_STM32F1/HAL_Servo_Stm32f1.cpp

Marlin/src/HAL/HAL_STM32F1/HAL_Servo_Stm32f1.h

Marlin/src/HAL/HAL_STM32F1/HAL_Stm32f1.cpp

Marlin/src/HAL/HAL_STM32F1/HAL_Stm32f1.h

Marlin/src/HAL/HAL_STM32F1/HAL_spi_Stm32f1.cpp

Marlin/src/HAL/HAL_STM32F1/HAL_timers_Stm32f1.cpp

Marlin/src/HAL/HAL_STM32F1/HAL_timers_Stm32f1.h

Marlin/src/HAL/HAL_STM32F1/README.md

Marlin/src/HAL/HAL_STM32F1/SanityCheck_Stm32f1.h

Marlin/src/HAL/HAL_STM32F1/endstop_interrupts.h

Marlin/src/HAL/HAL_STM32F1/fastio_Stm32f1.h

Marlin/src/HAL/HAL_STM32F1/persistent_store_impl.cpp

Marlin/src/HAL/HAL_STM32F1/spi_pins.h

Marlin/src/HAL/HAL_STM32F1/watchdog_Stm32f1.cpp

Marlin/src/HAL/HAL_STM32F1/watchdog_Stm32f1.h

Marlin/src/HAL/HAL_SanityCheck.h

Marlin/src/HAL/HAL_spi_pins.h

Marlin/src/config/examples/stm32f103ret6/Configuration.h

Marlin/src/core/boards.h