Re-arranging VCP/IO/EXTI files in preparation for AT32 (#12289)

* Re-arranging VCP files in preparation for AT32

* Tab size 4

* Adding ADC driver for AT32F43x

* RCC code here is STM32 specific.

* Adding rcc.c for AT32

* pwm_output.c has very specific MCU coupling - to be re factored.

* Separating exti.c

* Split up io.c int stm32/io_stm32.c and at32/io_at32.c

* Adding in VCP files for AT32 and move timer

- note will require more cleanup

* Solving for sanity checks

* Inadvertent inclusion of timer.c for HAL

* rcc.c, timer.c and moving other spevific files out of the driver directory

* Adding I2C drivers

* Formatting

* ws2811 driver and usb_msc driver skeleton

src/main/fc/tasks.c

@@ -103,14 +103,7 @@
 #endif
 
 #ifdef USE_USB_CDC_HID
-//TODO: Make it platform independent in the future
-#ifdef STM32F4
-#include "vcpf4/usbd_cdc_vcp.h"
-#include "usbd_hid_core.h"
-#elif defined(STM32F7)
-#include "usbd_cdc_interface.h"
-#include "usbd_hid.h"
-#endif
+#include "io/usb_cdc_hid.h"
 #endif
 
 #include "tasks.h"