ARM: dts: imx6qdl-udoo: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6dl-udoo.dts

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
  * Author: Fabio Estevam <fabio.estevam@freescale.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 /dts-v1/;
 #include "imx6dl.dtsi"

arch/arm/boot/dts/imx6q-udoo.dts

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
  * Author: Fabio Estevam <fabio.estevam@freescale.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 /dts-v1/;
 #include "imx6q.dtsi"

arch/arm/boot/dts/imx6qdl-udoo.dtsi

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
  * Author: Fabio Estevam <fabio.estevam@freescale.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 
 / {