Decouple USB events from the USB interrupt handler. (#10437)

tmk_core/protocol/chibios/usb_main.h

@@ -37,6 +37,17 @@ void init_usb_driver(USBDriver *usbp);
 /* Restart the USB driver and bus */
 void restart_usb_driver(USBDriver *usbp);
 
+/* ---------------
+ * USB Event queue
+ * ---------------
+ */
+
+/* Initialisation of the FIFO */
+void usb_event_queue_init(void);
+
+/* Task to dequeue and execute any handlers for the USB events on the main thread */
+void usb_event_queue_task(void);
+
 /* ---------------
  * Keyboard header
  * ---------------