Update hcd-ehci, dcd-dwc2 and examples.

1. Add some example Msh commands.
2. Fix device enumeration on EXT hub.
3. Re-file some templates.
4. Extend end-point number of dwc2 device driver.
5. Re-file rndis_host implementation includes
   a. rt_mutex_take in ISR
   b. 2rd pmsg is unaligned issue.
   c. destroy u0 ethernet resource after removing dongle.

class/hub/usbh_hub.c

@@ -299,7 +299,9 @@ static void hub_int_complete_callback(void *arg, int nbytes)
 {
     struct usbh_hub *hub = (struct usbh_hub *)arg;
 
-    if (nbytes > 0) {
+    // >=0 can pass device enumeration on EXT hub.
+    if (nbytes >= 0)
+    {
         usbh_hub_thread_wakeup(hub);
     }
 }