arm64: boot: dts: xilinx: zynqmp: add license headers

Add license headers to all zynqmp dts files that are missing them. Files
were found with:

	grep -L -r -m 1 '^// SPDX' arch/arm64/boot/dts/xilinx/zynqmp*

Signed-off-by: David Lechner <dlechner@baylibre.com>

Author: dlech

arch/arm64/boot/dts/xilinx/zynqmp-adrv9009-zu11eg-reva.dtsi

@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * dts file for ADRV9009-ZU11EG System on Module
  *
  * Copyright (C) 2019 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 /dts-v1/;

arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revB-ad9361-fmcomms2-3.dts

@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * dts file for FMCOMMS2/3 AD9361 on Xilinx ZynqMP ZCU102 RevB
  *
  * Copyright (C) 2016 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include "zynqmp-zcu102-revB.dts"

arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revB-ad9364-fmcomms4.dts

@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * dts file for FMCOMMS4 AD9364 on Xilinx ZynqMP ZCU102 RevB
  *
  * Copyright (C) 2016 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include "zynqmp-zcu102-revB.dts"

arch/arm64/boot/dts/xilinx/zynqmp-zcu102-revB-adrv9363.dts

@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * dts file for ADRV9363 - AD9363 on Xilinx ZynqMP ZCU102 RevB
  *
  * Copyright (C) 2017 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include "zynqmp-zcu102-revB-ad9361-fmcomms2-3.dts"