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/renesas/alt/alt.c b/board/renesas/alt/alt.c
index 4b783b0..86e9d24 100644
--- a/board/renesas/alt/alt.c
+++ b/board/renesas/alt/alt.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * board/renesas/alt/alt.c
  *
  * Copyright (C) 2014, 2015 Renesas Electronics Corporation
- *
- * SPDX-License-Identifier: GPL-2.0
  */
 
 #include <common.h>
diff --git a/board/renesas/alt/alt_spl.c b/board/renesas/alt/alt_spl.c
index f893a49..4260dff 100644
--- a/board/renesas/alt/alt_spl.c
+++ b/board/renesas/alt/alt_spl.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * board/renesas/alt/alt_spl.c
  *
  * Copyright (C) 2018 Marek Vasut <marek.vasut@gmail.com>
- *
- * SPDX-License-Identifier: GPL-2.0
  */
 
 #include <common.h>
diff --git a/board/renesas/alt/qos.c b/board/renesas/alt/qos.c
index 3323c3a..2f65750 100644
--- a/board/renesas/alt/qos.c
+++ b/board/renesas/alt/qos.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * board/renesas/alt/qos.c
  *
  * Copyright (C) 2014 Renesas Electronics Corporation
  *
- * SPDX-License-Identifier: GPL-2.0
- *
  */
 
 #include <common.h>
diff --git a/board/renesas/alt/qos.h b/board/renesas/alt/qos.h
index 9a6c046..d92c437 100644
--- a/board/renesas/alt/qos.h
+++ b/board/renesas/alt/qos.h
@@ -1,7 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2013 Renesas Electronics Corporation
- *
- * SPDX-License-Identifier: GPL-2.0
  */
 
 #ifndef __QOS_H__