arm: zynq: Add device-type property for zynq ethernet phy nodes

Mention device-type = "ethernet-phy", as qemu will need this in absence
of compatible.

Signed-off-by: Sai Pavan Boddu <saipava@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynq-zybo.dts b/arch/arm/dts/zynq-zybo.dts
index d59a383..f3eebb0 100644
--- a/arch/arm/dts/zynq-zybo.dts
+++ b/arch/arm/dts/zynq-zybo.dts
@@ -48,6 +48,7 @@
 
 	ethernet_phy: ethernet-phy@0 {
 		reg = <0>;
+		device_type = "ethernet-phy";
 	};
 };