ARM: dts: BCM53573: Add Ethernet interfaces links

BCM53573 has 2 Ethernet interfaces each connected to one of switch ports
in the default design. They both use fixed links.

An exception are Luxul XAP devices that have switch replaced by a single
PHY.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20230724101227.5420-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

arch/arm/boot/dts/broadcom/bcm47189-luxul-xap-1440.dts

@@ -50,6 +50,8 @@
 	phy-mode = "rgmii";
 	phy-handle = <&bcm54210e>;
 
+	/delete-node/ fixed-link;
+
 	mdio {
 		/delete-node/ switch@1e;
 

arch/arm/boot/dts/broadcom/bcm47189-luxul-xap-810.dts

@@ -86,6 +86,8 @@
 	phy-mode = "rgmii";
 	phy-handle = <&bcm54210e>;
 
+	/delete-node/ fixed-link;
+
 	mdio {
 		/delete-node/ switch@1e;
 

arch/arm/boot/dts/broadcom/bcm53573.dtsi

@@ -181,6 +181,12 @@
 
 		gmac0: ethernet@5000 {
 			reg = <0x5000 0x1000>;
+			phy-mode = "internal";
+
+			fixed-link {
+				speed = <1000>;
+				full-duplex;
+			};
 
 			mdio {
 				#address-cells = <1>;
@@ -237,6 +243,12 @@
 
 		gmac1: ethernet@b000 {
 			reg = <0xb000 0x1000>;
+			phy-mode = "internal";
+
+			fixed-link {
+				speed = <1000>;
+				full-duplex;
+			};
 		};
 
 		pmu@12000 {