This commits add the iopsys anywan support. The uci-default script
in target is deprecated post this commit and the handling for
generating board.json and then the network uci is done via the
45-iopsys-network file.

The change in the config_generate is necessary since the option
type is currently not handled for wan section of the board.json.

The uci default script to generate device section for ethernet
ports is updated to handle anywan as well.