arm64: dts: ti: k3-am68-sk-base-board: Add alias for MCU CPSW2G

Add alias for the MCU CPSW2G port to enable Linux to fetch MAC Address
for the port directly from U-Boot.
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
Link: https://lore.kernel.org/r/20231115085913.3585740-1-s-vadapalli@ti.comSigned-off-by: Nishanth Menon <nm@ti.com>

arch/arm64/boot/dts/ti/k3-am68-sk-base-board.dts

@@ -31,6 +31,7 @@ aliases {
 		can1 = &mcu_mcan1;
 		can2 = &main_mcan6;
 		can3 = &main_mcan7;
+		ethernet0 = &cpsw_port1;
 	};
 
 	vusb_main: regulator-vusb-main5v0 {