net: shell: iface: Allow user to set the default interface

It is useful in testing to allow user to change the default
network interface by "net iface default <index>".
Also print out the default interface for "net iface" and
"net iface default" commands.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
1 file changed