ARM: dts: NSP: Switch to port 8 for CPU port

Now that we have added support for pre-pended Broadcom tags with commit
1160603960 ("net: dsa: b53: Support prepended Broadcom tags") we can
switch all the Northstar Plus reference boards to use port 8 for the CPU
port. This allows us to prepare room for supporting the Flow Accelerator
2 NAPT offload, and frees up port 5 to be made fully configurable for
the modes that it supports: internal, SGMII, RGMII etc.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm958623hr.dts

@@ -208,10 +208,10 @@
 			reg = <4>;
 		};
 
-		port@5 {
-			ethernet = <&amac0>;
+		port@8 {
+			ethernet = <&amac2>;
 			label = "cpu";
-			reg = <5>;
+			reg = <8>;
 			fixed-link {
 				speed = <1000>;
 				full-duplex;