stmhal: Hookup USB_VCP.any().

Thanks to Dave Hylands for this patch.

stmhal/usb.c

@@ -255,6 +255,7 @@ mp_obj_t pyb_usb_vcp___exit__(uint n_args, const mp_obj_t *args) {
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_usb_vcp___exit___obj, 4, 4, pyb_usb_vcp___exit__);
 
 STATIC const mp_map_elem_t pyb_usb_vcp_locals_dict_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR_any), (mp_obj_t)&pyb_usb_vcp_any_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_usb_vcp_send_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_usb_vcp_recv_obj },
     /// \method read([nbytes])