rtc: maxim: Add SPDX license identifiers

Replace GPL v2.0+ license statements with SPDX license
identifiers.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-max77686.c

-/*
- * RTC driver for Maxim MAX77686 and MAX77802
- *
- * Copyright (C) 2012 Samsung Electronics Co.Ltd
- *
- *  based on rtc-max8997.c
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX77686 and MAX77802
+//
+// Copyright (C) 2012 Samsung Electronics Co.Ltd
+//
+//  based on rtc-max8997.c
 
 #include <linux/i2c.h>
 #include <linux/slab.h>

drivers/rtc/rtc-max8997.c

-/*
- * RTC driver for Maxim MAX8997
- *
- * Copyright (C) 2013 Samsung Electronics Co.Ltd
- *
- *  based on rtc-max8998.c
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8997
+//
+// Copyright (C) 2013 Samsung Electronics Co.Ltd
+//
+//  based on rtc-max8998.c
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 

drivers/rtc/rtc-max8998.c

-/*
- * RTC driver for Maxim MAX8998
- *
- * Copyright (C) 2010 Samsung Electronics Co.Ltd
- * Author: Minkyu Kang <mk7.kang@samsung.com>
- * Author: Joonyoung Shim <jy0922.shim@samsung.com>
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8998
+//
+// Copyright (C) 2010 Samsung Electronics Co.Ltd
+// Author: Minkyu Kang <mk7.kang@samsung.com>
+// Author: Joonyoung Shim <jy0922.shim@samsung.com>
 
 #include <linux/module.h>
 #include <linux/i2c.h>