at91: use SPDX license identifiers on DTS files

Use SPDX license tags to allow machines to check licenses.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/at91/files/arch/arm/boot/dts/at91-q5xr5.dts

@@ -1,10 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * q5xr5.dts - Device Tree file for Exegin Q5xR5 board
  *
  * Copyright (C) 2014 Owen Kirby <osk@exegin.com>
- *
- * Licensed under GPLv2.
  */
+
 /dts-v1/;
 #include "at91sam9g20.dtsi"
 

target/linux/at91/files/arch/arm/boot/dts/lmu5000.dts

@@ -1,10 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * lmu5000.dst - Device Tree file for CalAmp LMU5000 board
  *
  * Copyright (C) 2013 Adam Porter <porter.adam@gmail.com>
- *
- * Licensed under GPLv2.
  */
+
 /dts-v1/;
 #include "at91sam9g20.dtsi"
 

target/linux/at91/files/arch/arm/boot/dts/wb45n.dts

@@ -1,10 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * wb45n.dts - Device Tree file for WB45NBT board
  *
  *  Copyright (C) 2015 Laird
- *
- * Licensed under GPLv2 or later.
  */
+
 /dts-v1/;
 #include "at91sam9g25.dtsi"
 

target/linux/at91/files/arch/arm/boot/dts/wb50n.dts

@@ -1,10 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * wb50n.dts - Device Tree file for wb50n board
  *
  *  Copyright (C) 2015 Laird
- *
- * Licensed under GPLv2 or later.
  */
+
 /dts-v1/;
 #include "wb50n.dtsi"
 

target/linux/at91/files/arch/arm/boot/dts/wb50n.dtsi

@@ -1,10 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * wb50n.dts - Device Tree file for wb50n board
  *
  *  Copyright (C) 2015 Laird
- *
- * Licensed under GPLv2 or later.
  */
+
 #include "sama5d31.dtsi"
 
 / {