add windows driver for cdc

add simple echo cdc serial demo
add cdc device send/receive API
refractor descriptor
refractor cdc.h
add usbd driver function
- init
- bus_reset

tinyusb/device/usbd.h

@@ -63,11 +63,12 @@
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
 typedef struct {
+  void (* const init) (void);
   tusb_error_t (* const open)(uint8_t, tusb_descriptor_interface_t const *, uint16_t*);
   tusb_error_t (* const control_request) (uint8_t, tusb_control_request_t const *);
   void (* const isr) (endpoint_handle_t, tusb_event_t, uint32_t);
-//  void (* const close) (uint8_t);
-} device_class_driver_t;
+  void (* const bus_reset) (uint8_t);
+} usbd_class_driver_t;
 
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION