ARM: shmobile: bockw: fixup ether node naming

According to the ePAPR spec,
the node name should be "ethernet", not "lan0".
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7778-bockw-reference.dts

@@ -39,7 +39,7 @@ fixedregulator3v3: fixedregulator@0 {
 		regulator-always-on;
 	};
 
-	lan0@18300000 {
+	ethernet@18300000 {
 		compatible = "smsc,lan9220", "smsc,lan9115";
 		reg = <0x18300000 0x1000>;