ARM: dts: armada-375: Fixup ethernet child DT warning

Child of mvpp2 ethernet do not have a reg property so the unit name
should not contain an address: remove them.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm/boot/dts/armada-375.dtsi

@@ -224,13 +224,13 @@ ethernet: ethernet@f0000 {
 				clock-names = "pp_clk", "gop_clk";
 				status = "disabled";
 
-				eth0: eth0@c4000 {
+				eth0: eth0 {
 					interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
 					port-id = <0>;
 					status = "disabled";
 				};
 
-				eth1: eth1@c5000 {
+				eth1: eth1 {
 					interrupts = <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>;
 					port-id = <1>;
 					status = "disabled";