arm: zynq: Sync up licenses with mainline kernel

Use different location for SPDX line. Also update dates for new mainline
DTS files.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynq-zc770-xm010.dts b/arch/arm/dts/zynq-zc770-xm010.dts
index cc5ba98..0c364df 100644
--- a/arch/arm/dts/zynq-zc770-xm010.dts
+++ b/arch/arm/dts/zynq-zc770-xm010.dts
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Xilinx ZC770 XM010 board DTS
  *
- * Copyright (C) 2013 - 2015 Xilinx, Inc.
- *
- * SPDX-License-Identifier:	GPL-2.0+
+ * Copyright (C) 2013-2018 Xilinx, Inc.
  */
 /dts-v1/;
 #include "zynq-7000.dtsi"