Strip tabs and trailing white spaces, and fix end of files (#748)

* format: Strip trailing whitespaces

We want to get rid of trailing whitespaces completly as they make just git
noice. Much better to start using automated tools to get rid of them once and
not getting them back again. This way git history will be cleaner and review
easier.

Commit was generated with:

    pre-commit run --all-files trailing-whitespace

* format: Files should have exactly one new line end of them

It is good practice that every file has one new line. It is not now days so
mandatory but it also is not nice if file has lot of newlines end of it. We will
use pre-commit which takes automatically care about this so let's fix all.

Commit was generated with:

    pre-commit run --all-files end-of-file-fixer

* format: Convert tabs to spaces

Project mostly use spaces over tabs. When mixing tabs and spaces this usually
makes formatting issues and also when changing those in commits it will make lot
of git noise. We will force spaces most of the time and use pre-commit to fix.

Commit was generated with:

    pre-commit run --all-files remove-tabs

---------

Co-authored-by: Kari Argillander <kari.argillander@fidelix.com>

ports/stm32f4xx/system_stm32f4xx.h

@@ -4,8 +4,8 @@
   * @author  MCD Application Team
   * @version V1.0.0
   * @date    30-September-2011
-  * @brief   CMSIS Cortex-M4 Device System Source File for STM32F4xx devices.  
-  ******************************************************************************  
+  * @brief   CMSIS Cortex-M4 Device System Source File for STM32F4xx devices.
+  ******************************************************************************
   * @attention
   *
   * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
@@ -16,8 +16,8 @@
   * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
   *
   * <h2><center>&copy; COPYRIGHT 2011 STMicroelectronics</center></h2>
-  ******************************************************************************  
-  */ 
+  ******************************************************************************
+  */
 
 /** @addtogroup CMSIS
   * @{
@@ -25,8 +25,8 @@
 
 /** @addtogroup stm32f4xx_system
   * @{
-  */  
-  
+  */
+
 /**
   * @brief Define to prevent recursive inclusion
   */
@@ -35,7 +35,7 @@
 
 #ifdef __cplusplus
  extern "C" {
-#endif 
+#endif
 
 /** @addtogroup STM32F4xx_System_Includes
   * @{
@@ -76,7 +76,7 @@ extern uint32_t SystemCoreClock;          /*!< System Clock Frequency (Core Cloc
 /** @addtogroup STM32F4xx_System_Exported_Functions
   * @{
   */
-  
+
 extern void SystemInit(void);
 extern void SystemCoreClockUpdate(void);
 extern void System_LSE_Init(void);
@@ -94,8 +94,8 @@ extern void System_LSE_Init(void);
 /**
   * @}
   */
-  
+
 /**
   * @}
-  */  
+  */
 /******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/