ARM: dts: zynq: Set correct manufacturer for ZedBoard and MicroZed boards

Both boards are made by Avnet, Inc. So add an additional
value to the compatible property

Signed-off-by: Luis Araneda <luaraneda@gmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-zed.dts

@@ -8,7 +8,7 @@
 
 / {
 	model = "Zynq Zed Development Board";
-	compatible = "xlnx,zynq-zed", "xlnx,zynq-7000";
+	compatible = "avnet,zynq-zed", "xlnx,zynq-zed", "xlnx,zynq-7000";
 
 	aliases {
 		ethernet0 = &gem0;