team: team should sync the port's uc/mc addrs when add a port

There is an issue when we use mavtap over team:
When we replug nic links from team0, the real nics's mc list will not
include the maddr for macvtap any more. then we can't receive pkts to
macvtap device, as they are filterred by mc list of nic.

In Bonding Driver, it syncs the uc/mc addrs in bond_enslave().

We will fix this issue on team by adding the port's uc/mc addrs sync in
team_port_add.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>