Userspace handling is deprecated. NVMEM allows more flexibility in terms
of exotic setups while keeping correct MAC addresses.
env-size taken from file in uboot-envtools.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/22107
Signed-off-by: Robert Marko <robimarko@gmail.com>