libteam: introduce ream_refresh

New function used to refresh internal lists and to call connected
handlers.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
teamd: look for existing ports before adding new ones

This is handy when we are doing take over of team device. Without this,
teamd is not aware of existing ports.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
teamd: do not remove ports from team dev in case of take over mode

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