arm64: zynqmp: Update Copyright years to 2021

Trivial change for all files I have touched recently.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynqmp.dtsi b/arch/arm/dts/zynqmp.dtsi
index deb3fa3..47ffdf1 100644
--- a/arch/arm/dts/zynqmp.dtsi
+++ b/arch/arm/dts/zynqmp.dtsi
@@ -2,7 +2,7 @@
 /*
  * dts file for Xilinx ZynqMP
  *
- * (C) Copyright 2014 - 2020, Xilinx, Inc.
+ * (C) Copyright 2014 - 2021, Xilinx, Inc.
  *
  * Michal Simek <michal.simek@xilinx.com>
  *