[bsp][stm32]fix the error when open uart6 alonely!

bsp/stm32/libraries/HAL_Drivers/drv_usart.c

@@ -19,7 +19,7 @@
 #include <drv_log.h>
 
 #if !defined(BSP_USING_UART1) && !defined(BSP_USING_UART2) && !defined(BSP_USING_UART3) \
-    && !defined(BSP_USING_UART4) && !defined(BSP_USING_UART5) && !defined(BSP_USING_LPUART1)
+    && !defined(BSP_USING_UART4) && !defined(BSP_USING_UART5) && !defined(BSP_USING_UART6) && !defined(BSP_USING_LPUART1)
 #error "Please define at least one BSP_USING_UARTx"
 /* this driver can be disabled at menuconfig → RT-Thread Components → Device Drivers */
 #endif