ARM: dts: imx53-ard: Correct Ethernet node name

make dtbs_check:

    lan9220@f4000000: $nodename:0: 'lan9220@f4000000' does not match '^ethernet(@.*)?$'

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx53-ard.dts

@@ -24,7 +24,7 @@
 		reg = <0xf4000000 0x3ff0000>;
 		ranges;
 
-		lan9220@f4000000 {
+		ethernet@f4000000 {
 			compatible = "smsc,lan9220", "smsc,lan9115";
 			reg = <0xf4000000 0x2000000>;
 			phy-mode = "mii";