Add Zonestar/Anet LCD for SKR mini E3 (#15931)

Marlin/src/HAL/HAL_STM32F1/HAL.cpp

Marlin/src/HAL/HAL_STM32F1/timers.h

Marlin/src/core/boards.h

Marlin/src/inc/SanityCheck.h

Marlin/src/pins/lpc1768/pins_BTT_SKR.h

Marlin/src/pins/lpc1768/pins_BTT_SKR_V1_1.h

Marlin/src/pins/lpc1768/pins_BTT_SKR_V1_3.h

Marlin/src/pins/pins.h

Marlin/src/pins/stm32/pins_BTT_BTT002_V1_0.h

Marlin/src/pins/stm32/pins_BTT_SKR_E3_DIP.h

Marlin/src/pins/stm32/pins_BTT_SKR_MINI_E3.h

Marlin/src/pins/stm32/pins_BTT_SKR_MINI_E3_V1_0.h

Marlin/src/pins/stm32/pins_BTT_SKR_MINI_E3_V1_2.h

Marlin/src/pins/stm32/pins_BTT_SKR_MINI_V1_1.h

Marlin/src/pins/stm32/pins_BTT_SKR_PRO_V1_1.h

buildroot/share/tests/STM32F103RC_bigtree_NOUSB-tests