teamnl: update help message
teamnl: update help message

Update help message so people could know we support port name directly.

Signed-off-by: Hangbin Liu <f18dd0be96fb7338348dc2439a86c9a4ef8ef3b9@gmail.com>
Signed-off-by: Jiri Pirko <1b548d10035ae428195c41f5d55eedb1437ccd8a@mellanox.com>

jpirko/libteam,jpirko/libteam,jpirko/libteam