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/drivers/demo/Makefile b/drivers/demo/Makefile
index 171ddf3..9acd918 100644
--- a/drivers/demo/Makefile
+++ b/drivers/demo/Makefile
@@ -1,8 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (c) 2013 Google, Inc
-#
-# SPDX-License-Identifier:	GPL-2.0+
-#
 
 obj-y += demo-uclass.o demo-pdata.o
 obj-$(CONFIG_DM_DEMO_SIMPLE) += demo-simple.o
diff --git a/drivers/demo/demo-pdata.c b/drivers/demo/demo-pdata.c
index e92841d..2f434f8 100644
--- a/drivers/demo/demo-pdata.c
+++ b/drivers/demo/demo-pdata.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2013 Google, Inc
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/drivers/demo/demo-shape.c b/drivers/demo/demo-shape.c
index 7e71f3b..98b6446 100644
--- a/drivers/demo/demo-shape.c
+++ b/drivers/demo/demo-shape.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2013 Google, Inc
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/drivers/demo/demo-simple.c b/drivers/demo/demo-simple.c
index d05b1df..68972c7 100644
--- a/drivers/demo/demo-simple.c
+++ b/drivers/demo/demo-simple.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2013 Google, Inc
  *
  * (C) Copyright 2012
  * Pavel Herrmann <morpheus.ibis@gmail.com>
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
diff --git a/drivers/demo/demo-uclass.c b/drivers/demo/demo-uclass.c
index 3341572..3b8439b 100644
--- a/drivers/demo/demo-uclass.c
+++ b/drivers/demo/demo-uclass.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2013 Google, Inc
  *
  * (C) Copyright 2012
  * Pavel Herrmann <morpheus.ibis@gmail.com>
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>