[F1] Update system source file

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

Author: fpistm

system/STM32F1xx/system_stm32f1xx.c

@@ -2,8 +2,6 @@
   ******************************************************************************
   * @file    system_stm32f1xx.c
   * @author  MCD Application Team
-  * @version V4.2.0
-  * @date    31-March-2017
   * @brief   CMSIS Cortex-M3 Device Peripheral Access Layer System Source File.
   *
   * 1.  This file provides two functions and one global variable to be called from
@@ -35,29 +33,13 @@
   ******************************************************************************
   * @attention
   *
-  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
+  * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics.
+  * All rights reserved.</center></h2>
   *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  * This software component is licensed by ST under BSD 3-Clause license,
+  * the "License"; You may not use this file except in compliance with the
+  * License. You may obtain a copy of the License at:
+  *                        opensource.org/licenses/BSD-3-Clause
   *
   ******************************************************************************
   */
@@ -132,14 +114,15 @@
   * @{
   */
 
-/*******************************************************************************
-*  Clock Definitions
-*******************************************************************************/
-#if defined(STM32F100xB) ||defined(STM32F100xE)
-  uint32_t SystemCoreClock         = 24000000U;        /*!< System Clock Frequency (Core Clock) */
-#else /*!< HSI Selected as System Clock source */
-  uint32_t SystemCoreClock         = 72000000U;        /*!< System Clock Frequency (Core Clock) */
-#endif
+  /* This variable is updated in three ways:
+      1) by calling CMSIS function SystemCoreClockUpdate()
+      2) by calling HAL API function HAL_RCC_GetHCLKFreq()
+      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency
+         Note: If you use this function to configure the system clock; then there
+               is no need to call the 2 first functions listed above, since SystemCoreClock
+               variable is updated automatically.
+  */
+uint32_t SystemCoreClock = 16000000;
 
 const uint8_t AHBPrescTable[16U] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
 const uint8_t APBPrescTable[8U] =  {0, 0, 0, 0, 1, 2, 3, 4};