With d2b6bf1416 ("ramips: fix image validation errors") the board
name was changed to fix an image validation error. But this change
wasn't applied to all other files using the board name, which broke
sysupgrade.
Revert this change and use the former board name in the metadata
instead.
Signed-off-by: Mathias Kresin <dev@kresin.me>
99f1097c0a