ARM: dts: rk3228-evb: Fix the compiling error

This patch solves the following error:
arch/arm/boot/dts/rk3228-evb.dtb: ERROR (phandle_references): Reference to non-existent node or label "phy0"

Fixess db40f15b ("ARM: dts: rk3228-evb: Enable the integrated PHY for gmac")
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm/boot/dts/rk3228-evb.dts

@@ -76,7 +76,7 @@ &gmac {
 	clock_in_out = "output";
 	phy-supply = <&vcc_phy>;
 	phy-mode = "rmii";
-	phy-handle = <&phy0>;
+	phy-handle = <&phy>;
 	status = "okay";
 
 	mdio {
@@ -84,7 +84,7 @@ mdio {
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-		phy@0 {
+		phy: phy@0 {
 			compatible = "ethernet-phy-id1234.d400", "ethernet-phy-ieee802.3-c22";
 			reg = <0>;
 			clocks = <&cru SCLK_MAC_PHY>;