Add WCH CH32V307 port

Add WCH mcu submodule
Add CH32V307V-R1-1v0 bsp

hw/bsp/ch32v307/ch32v30x_it.c

@@ -0,0 +1,49 @@
+/********************************** (C) COPYRIGHT *******************************
+* File Name          : ch32v30x_it.c
+* Author             : WCH
+* Version            : V1.0.0
+* Date               : 2021/06/06
+* Description        : Main Interrupt Service Routines.
+* Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
+* SPDX-License-Identifier: Apache-2.0
+*******************************************************************************/
+#include "ch32v30x_it.h"
+
+void NMI_Handler(void) __attribute__((naked));
+void HardFault_Handler(void) __attribute__((naked));
+
+/*********************************************************************
+ * @fn      NMI_Handler
+ *
+ * @brief   This function handles NMI exception.
+ *
+ * @return  none
+ */
+void NMI_Handle(void){
+      __asm volatile ("call NMI_Handler_impl; mret");
+}
+
+__attribute__((used)) void NMI_Handler_impl(void)
+{
+
+}
+
+/*********************************************************************
+ * @fn      HardFault_Handler
+ *
+ * @brief   This function handles Hard Fault exception.
+ *
+ * @return  none
+ */
+void HardFault_Handler(void){
+      __asm volatile ("call HardFault_Handler_impl; mret");
+}
+
+__attribute__((used)) void HardFault_Handler_impl(void)
+{
+  while (1)
+  {
+  }
+}
+
+