NVMEM on MMC was added in dts but the corresponding option was not added
to the config.
Fixes: ee5999c ("treewide: linksys: use nvmem MAC for hw_mac_addr") Signed-off-by: Rosen Penev <rosenp@gmail.com> Link: https://github.com/openwrt/openwrt/pull/22539 Signed-off-by: Robert Marko <robert.marko@sartura.hr>