[STM32][RTC] add support for STM32L0 series. (#5994)

* [STM32][RTC] add support for STM32L0 series.

* Update drv_rtc.c

bsp/stm32/libraries/HAL_Drivers/drv_rtc.c

@@ -179,7 +179,7 @@ static rt_err_t rt_rtc_config(void)
         RTC_Handler.Init.OutPut = RTC_OUTPUT_DISABLE;
         RTC_Handler.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
         RTC_Handler.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
-#elif defined(SOC_SERIES_STM32F2) || defined(SOC_SERIES_STM32F4) || defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32WL) || defined(SOC_SERIES_STM32H7) || defined (SOC_SERIES_STM32WB)
+#elif defined(SOC_SERIES_STM32F2) || defined(SOC_SERIES_STM32F4) || defined(SOC_SERIES_STM32F7) || defined(SOC_SERIES_STM32L0) || defined(SOC_SERIES_STM32L4) || defined(SOC_SERIES_STM32WL) || defined(SOC_SERIES_STM32H7) || defined (SOC_SERIES_STM32WB)
 
         /* set the frequency division */
 #ifdef BSP_RTC_USING_LSI
@@ -193,7 +193,10 @@ static rt_err_t rt_rtc_config(void)
         RTC_Handler.Init.OutPut = RTC_OUTPUT_DISABLE;
         RTC_Handler.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
         RTC_Handler.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
+#else
+#warning "This series doesn't support yet!"
 #endif
+
         if (HAL_RTC_Init(&RTC_Handler) != HAL_OK)
         {
             return -RT_ERROR;