We cannot depend on CONFIG_OF in the module definition context as this symbol
is not defined for OpenWrt menuconfig. Depend on the targets that appear to
need the kmod-of-mdio module instead.
The target dependency list may not be complete, it is based on the build
failures encountered by the build bots.
Fixes: dc629d9cf5 ("kernel: fix kmod-switch-rtl8366-smi dependency")
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
56bd23cf52