net/mlx4_core: Dynamic VST to VST vlan/qos changes

Within VST mode, enable modifying the vlan and/or qos
for a VF without requiring unbind/rebind.

This requires firmware which supports the UPDATE_QP command.
(If the command is not available, we fall back to requiring
unbind/bind to activate these changes).

To avoid race conditions with modify-qp on QPs that are affected
by update-qp, this operation is performed on the comm_wq.

If the update operation succeeds for all the necessary QPs, a
vlan_unregister is performed for the abandoned vlan id.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>