ramips: mt7621-dts: remove incorrect ethphy4 node for WAVLINK WL-WN573HX1

The ethernet-phy@4 node doesn't exist for WAVLINK WL-WN573HX1. Remove it
and the duplicate gmac0 node.

Signed-off-by: Arınç ÜNAL <[email protected]>

target/linux/ramips/dts/mt7621_wavlink_wl-wn573hx1.dts

@@ -47,12 +47,6 @@
 	nvmem-cell-names = "mac-address";
 };
 
-&mdio {
-	ethphy4: ethernet-phy@4 {
-		reg = <4>;
-	};
-};
-
 &pcie {
 	status = "okay";
 };
@@ -119,17 +113,6 @@
 	};
 };
 
-&gmac0 {
-	nvmem-cells = <&macaddr_factory_3fff4>;
-	nvmem-cell-names = "mac-address";
-};
-
-&mdio {
-	ethphy4: ethernet-phy@4 {
-		reg = <4>;
-	};
-};
-
 &switch0 {
 	ports {
 		port@3 {