arm64: dts: Edge: disable gmac for Edge

Author: numbqq

arch/arm64/boot/dts/rockchip/rk3399-kedge-linux.dts

@@ -48,3 +48,7 @@
 	model = "Khadas Edge";
 	compatible = "khadas,edge", "rockchip,rk3399";
 };
+
+&gmac {
+	status = "disabled";
+};