Enable RTC for all platforms and add cli date command (#252)

* F2: enable RTC. Cli: add date command.

firmware/targets/f2/Inc/rtc.h

@@ -0,0 +1,58 @@
+/**
+  ******************************************************************************
+  * File Name          : RTC.h
+  * Description        : This file provides code for the configuration
+  *                      of the RTC instances.
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
+  * All rights reserved.</center></h2>
+  *
+  * This software component is licensed by ST under Ultimate Liberty license
+  * SLA0044, the "License"; You may not use this file except in compliance with
+  * the License. You may obtain a copy of the License at:
+  *                             www.st.com/SLA0044
+  *
+  ******************************************************************************
+  */
+/* Define to prevent recursive inclusion -------------------------------------*/
+#ifndef __rtc_H
+#define __rtc_H
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/* Includes ------------------------------------------------------------------*/
+#include "main.h"
+
+/* USER CODE BEGIN Includes */
+
+/* USER CODE END Includes */
+
+extern RTC_HandleTypeDef hrtc;
+
+/* USER CODE BEGIN Private defines */
+
+/* USER CODE END Private defines */
+
+void MX_RTC_Init(void);
+
+/* USER CODE BEGIN Prototypes */
+
+/* USER CODE END Prototypes */
+
+#ifdef __cplusplus
+}
+#endif
+#endif /*__ rtc_H */
+
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

firmware/targets/f2/Inc/stm32l4xx_hal_conf.h

@@ -67,7 +67,7 @@
 /*#define HAL_QSPI_MODULE_ENABLED   */
 /*#define HAL_QSPI_MODULE_ENABLED   */
 /*#define HAL_RNG_MODULE_ENABLED   */
-/*#define HAL_RTC_MODULE_ENABLED   */
+#define HAL_RTC_MODULE_ENABLED
 /*#define HAL_SAI_MODULE_ENABLED   */
 /*#define HAL_SD_MODULE_ENABLED   */
 /*#define HAL_SMBUS_MODULE_ENABLED   */