teamd: make teamd_get_port_by_ifname ifname argument const

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
teamd: introduce PortConfigDump control method

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
libteamdctl: cache reply strings into list

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
libteamdctl: introduce support for port config get

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
teamdctl: use new port config get function

Signed-off-by: Jiri Pirko <jiri@resnulli.us>