Remove old source code

guowenxue

2021-06-19 03929311976490307b02dca79dc8f21bdb9ac085

src/ISKv1_Led/Drivers/STM32F1xx_HAL_Driver/Inc/stm32f1xx_hal_exti.h does not exist in tree 47a20ee75dc642a603f9bc9c84b9720d7ad722cc