i2c: stm32: Fix copyrights

Uniformize STMicroelectronics copyrights headers and add SPDX
identifier.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-stm32.h

+// SPDX-License-Identifier: GPL-2.0
 /*
  * i2c-stm32.h
  *
  * Copyright (C) M'boumba Cedric Madianga 2017
+ * Copyright (C) STMicroelectronics 2017
  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
  *
- * License terms:  GNU General Public License (GPL), version 2
  */
 
 #ifndef _I2C_STM32_H

drivers/i2c/busses/i2c-stm32f4.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Driver for STMicroelectronics STM32 I2C controller
  *
@@ -6,11 +7,11 @@
  * http://www.st.com/resource/en/reference_manual/DM00031020.pdf
  *
  * Copyright (C) M'boumba Cedric Madianga 2016
+ * Copyright (C) STMicroelectronics 2017
  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
  *
  * This driver is based on i2c-st.c
  *
- * License terms:  GNU General Public License (GPL), version 2
  */
 
 #include <linux/clk.h>

drivers/i2c/busses/i2c-stm32f7.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Driver for STMicroelectronics STM32F7 I2C controller
  *
@@ -7,11 +8,11 @@
  * http://www.st.com/resource/en/reference_manual/dm00124865.pdf
  *
  * Copyright (C) M'boumba Cedric Madianga 2017
+ * Copyright (C) STMicroelectronics 2017
  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
  *
  * This driver is based on i2c-stm32f4.c
  *
- * License terms:  GNU General Public License (GPL), version 2
  */
 #include <linux/clk.h>
 #include <linux/delay.h>