mediatek: Fix writing U-Boot env on Buffalo WSR-2533DHP2

This fixes writing to the U-Boot environment by making the partition
writable and setting the correct flash sector size of 128K.

Signed-off-by: Hauke Mehrtens <[email protected]>

package/boot/uboot-envtools/files/mediatek

@@ -25,7 +25,7 @@ case "$board" in
 	ubootenv_add_uci_config "$envdev" "0x80000" "0x80000" "0x80000" "1"
 	;;
 buffalo,wsr-2533dhp2)
-	ubootenv_add_uci_config "/dev/mtd3" "0x0" "0x1000" "0x1000"
+	ubootenv_add_uci_config "/dev/mtd3" "0x0" "0x1000" "0x20000"
 	;;
 esac
 

target/linux/mediatek/dts/mt7622-buffalo-wsr-2533dhp2.dts

@@ -269,7 +269,6 @@
 			partition@140000 {
 				label = "Config";
 				reg = <0x140000 0x80000>;
-				read-only;
 			};
 
 			factory: partition@1c0000 {