增加对LCD屏幕的支持，并初始化RTC配置

Core/Inc/stm32f1xx_it.h

@@ -22,7 +22,7 @@
 #define __STM32F1xx_IT_H
 
 #ifdef __cplusplus
- extern "C" {
+extern "C" {
 #endif
 
 /* Private includes ----------------------------------------------------------*/
@@ -52,6 +52,7 @@ void MemManage_Handler(void);
 void BusFault_Handler(void);
 void UsageFault_Handler(void);
 void DebugMon_Handler(void);
+void DMA1_Channel3_IRQHandler(void);
 void DMA1_Channel4_IRQHandler(void);
 void DMA1_Channel5_IRQHandler(void);
 void USART1_IRQHandler(void);