You found an outdated thread:
For practical reason, I am suggesting to close this thread: The original thread is 2 years old and addresses mvebu on OpenWRT at a time when it was swconfig-based. OpenWRT for mvebu is now DSA-based since 2021, so config is now different, so this outdated thread content is only applicable to people, who have not updated OpenWRT on their mvebu for more than 3 years.
Sounds like you found the wrong forum. If you are interested in official linksys firmware, you should consider one of the linksys forum.