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/board/sbc8349/Makefile b/board/sbc8349/Makefile
index 3b2c389..c469174 100644
--- a/board/sbc8349/Makefile
+++ b/board/sbc8349/Makefile
@@ -1,8 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (c) 2006 Wind River Systems, Inc.
-#
-# SPDX-License-Identifier:	GPL-2.0+
-#
 
 obj-y += sbc8349.o
 obj-$(CONFIG_PCI) += pci.o
diff --git a/board/sbc8349/pci.c b/board/sbc8349/pci.c
index 9b1560b..b173c9c 100644
--- a/board/sbc8349/pci.c
+++ b/board/sbc8349/pci.c
@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * pci.c -- WindRiver SBC8349 PCI board support.
  * Copyright (c) 2006 Wind River Systems, Inc.
  * Copyright (C) 2006-2009 Freescale Semiconductor, Inc.
  *
  * Based on MPC8349 PCI support but w/o PIB related code.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <asm/mmu.h>
diff --git a/board/sbc8349/sbc8349.c b/board/sbc8349/sbc8349.c
index ef87f9f..b8ba29a 100644
--- a/board/sbc8349/sbc8349.c
+++ b/board/sbc8349/sbc8349.c
@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * sbc8349.c -- WindRiver SBC8349 board support.
  * Copyright (c) 2006-2007 Wind River Systems, Inc.
  *
  * Paul Gortmaker <paul.gortmaker@windriver.com>
  * Based on board/mpc8349emds/mpc8349emds.c (and previous 834x releases.)
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>