ramips: fix USW-Flex reversed switch-port order

Switch port order was reversed due to reading the internal labling
(which mismatches the one on the case).

Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ramips/dts/mt7621_ubnt_usw-flex.dts

@@ -65,12 +65,12 @@
 	ports {
 		port@0 {
 			status = "okay";
-			label = "lan1";
+			label = "lan5";
 		};
 
 		port@1 {
 			status = "okay";
-			label = "lan2";
+			label = "lan4";
 		};
 
 		port@2 {
@@ -80,12 +80,12 @@
 
 		port@3 {
 			status = "okay";
-			label = "lan4";
+			label = "lan2";
 		};
 
 		port@4 {
 			status = "okay";
-			label = "lan5";
+			label = "lan1";
 		};
 	};
 };