mlx4: Setting new port types after all interfaces unregistered

In port type change flow, need to set the new port types only after
all interfaces have finished the unregister process.
Otherwise, during unregister, one of the interfaces might issue a SET_PORT
command with wrong port types, it can cause bad FW behavior.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>