SPDX: Convert all of our single license tags to Linux Kernel style

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-imx/mx5/Makefile b/arch/arm/mach-imx/mx5/Makefile
index 4e305e9..1fc9c96 100644
--- a/arch/arm/mach-imx/mx5/Makefile
+++ b/arch/arm/mach-imx/mx5/Makefile
@@ -1,11 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0+
 #
 # (C) Copyright 2000-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # (C) Copyright 2009 Freescale Semiconductor, Inc.
-#
-# SPDX-License-Identifier:	GPL-2.0+
-#
 
 obj-y := soc.o clock.o
 obj-y += lowlevel_init.o
diff --git a/arch/arm/mach-imx/mx5/clock.c b/arch/arm/mach-imx/mx5/clock.c
index 284f6d4..427cb12 100644
--- a/arch/arm/mach-imx/mx5/clock.c
+++ b/arch/arm/mach-imx/mx5/clock.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2007
  * Sascha Hauer, Pengutronix
  *
  * (C) Copyright 2009 Freescale Semiconductor, Inc.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/arch/arm/mach-imx/mx5/lowlevel_init.S b/arch/arm/mach-imx/mx5/lowlevel_init.S
index f5bc672..b42cc3e 100644
--- a/arch/arm/mach-imx/mx5/lowlevel_init.S
+++ b/arch/arm/mach-imx/mx5/lowlevel_init.S
@@ -1,9 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright (C) 2007, Guennadi Liakhovetski <lg@denx.de>
  *
  * (C) Copyright 2009 Freescale Semiconductor, Inc.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <config.h>
diff --git a/arch/arm/mach-imx/mx5/mx53_dram.c b/arch/arm/mach-imx/mx5/mx53_dram.c
index 7e5fc42..39ac287 100644
--- a/arch/arm/mach-imx/mx5/mx53_dram.c
+++ b/arch/arm/mach-imx/mx5/mx53_dram.c
@@ -1,8 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2017  Beckhoff Automation GmbH & Co. KG
  * Patrick Bruenn <p.bruenn@beckhoff.com>
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/arch/arm/mach-imx/mx5/soc.c b/arch/arm/mach-imx/mx5/soc.c
index 2b63871..43d6c08 100644
--- a/arch/arm/mach-imx/mx5/soc.c
+++ b/arch/arm/mach-imx/mx5/soc.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2007
  * Sascha Hauer, Pengutronix
  *
  * (C) Copyright 2009 Freescale Semiconductor, Inc.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>