net/mlx5: E-Switch, Introduce HCA cap and E-Switch vport context

E-Switch vport context is unlike NIC vport context, managed by the
E-Switch manager or vport_group_manager and not by the NIC(VF) driver.

The E-Switch manager can access (read/modify) any of its vports
E-Switch context.

Currently E-Switch vport context includes only clietnt and server
vlan insertion and striping data (for later support of VST mode).

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>