Support custom Usb reenumerate (#500)

* Support custom USB reenumeration.

Co-Authored-By: xC0000005 <[email protected]>

Author: xC0000005

cores/arduino/stm32/usb/usbd_if.c

@@ -16,7 +16,7 @@
   * @retval None
   */
 
-void USBD_reenumerate(void)
+WEAK void USBD_reenumerate(void)
 {
 #ifndef USBD_REENUM_DISABLED
   /* Re-enumerate the USB */

variants/MALYANM200_F103CB/variant.cpp

@@ -95,6 +95,16 @@ void initVariant()
   digitalWrite(PB9, 1);
 }
 
+void USBD_reenumerate(void)
+{
+  pinMode(PB9, OUTPUT);
+  digitalWrite(PB9, HIGH);
+  delay(10);
+  digitalWrite(PB9, LOW);
+  delay(10);
+  digitalWrite(PB9, HIGH);
+}
+
 /**
   * @brief  System Clock Configuration
   *         The system Clock is configured as follow :