ARM: dts: am437x-idk-evm: get rid of phy_id property

The phy_id property is deprecated and phy-handle has to be used instead.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am437x-idk-evm.dts

@@ -499,10 +499,14 @@ &davinci_mdio {
 	pinctrl-0 = <&davinci_mdio_default>;
 	pinctrl-1 = <&davinci_mdio_sleep>;
 	status = "okay";
+
+	ethphy0: ethernet-phy@0 {
+		reg = <0>;
+	};
 };
 
 &cpsw_emac0 {
-	phy_id = <&davinci_mdio>, <0>;
+	phy-handle = <&ethphy0>;
 	phy-mode = "rgmii";
 };