Remove redundant macro definition.| 移除多余的宏定义.

bsp/stm32f10x/drivers/board.h

@@ -39,10 +39,6 @@
 
 // <<< Use Configuration Wizard in Context Menu >>>
 
-/* USART driver select. */
-#define RT_USING_UART1
-#define RT_USING_UART2
-#define RT_USING_UART3
 #define USING_BXCAN1
 
 void rt_hw_board_init(void);