ARM: dts: BCM53573: Add BCM53125 switch port 5

It's connected to the extra Ethernet interface.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20230723195416.7831-3-zajec5@gmail.comSigned-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

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

@@ -216,6 +216,16 @@ port@4 {
 							reg = <4>;
 						};
 
+						port@5 {
+							reg = <5>;
+							ethernet = <&gmac1>;
+
+							fixed-link {
+								speed = <1000>;
+								full-duplex;
+							};
+						};
+
 						port@8 {
 							reg = <8>;
 							ethernet = <&gmac0>;