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/synopsys/axs10x/Makefile b/board/synopsys/axs10x/Makefile
index e29d520..340e12c 100644
--- a/board/synopsys/axs10x/Makefile
+++ b/board/synopsys/axs10x/Makefile
@@ -1,8 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (C) 2013-2016 Synopsys, Inc. All rights reserved.
-#
-# SPDX-License-Identifier:	GPL-2.0+
-#
 
 obj-y	+= axs10x.o
 obj-$(CONFIG_CMD_NAND) += nand.o
diff --git a/board/synopsys/axs10x/axs10x.c b/board/synopsys/axs10x/axs10x.c
index 18f7666..af78127 100644
--- a/board/synopsys/axs10x/axs10x.c
+++ b/board/synopsys/axs10x/axs10x.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/board/synopsys/axs10x/axs10x.h b/board/synopsys/axs10x/axs10x.h
index 8e8c41f..69541cc 100644
--- a/board/synopsys/axs10x/axs10x.h
+++ b/board/synopsys/axs10x/axs10x.h
@@ -1,7 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright (C) 2015 Synopsys, Inc. All rights reserved.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #ifndef _BOARD_SYNOPSYS_AXS10X_H
diff --git a/board/synopsys/axs10x/nand.c b/board/synopsys/axs10x/nand.c
index 4be52e2..8108460 100644
--- a/board/synopsys/axs10x/nand.c
+++ b/board/synopsys/axs10x/nand.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <bouncebuf.h>