ramips: fix port labels for Xiaomi Mi Router 4

The OEM assignment of LAN ports is swapped.

Fixes: c2a7bb52

 ("ramips: mt7621: add support for Xiaomi Mi Router 4")
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ramips/dts/mt7621_xiaomi_mi-router-4.dts

@@ -72,12 +72,12 @@
 	ports {
 		port@1 {
 			status = "okay";
-			label = "lan1";
+			label = "lan2";
 		};
 
 		port@2 {
 			status = "okay";
-			label = "lan2";
+			label = "lan1";
 		};
 
 		port@4 {