net/mlx5: Bridge, implement infrastructure for vlans

Establish all the necessary infrastructure for implementing vlan matching
and vlan push/pop in following patches:

- Add new per-vport struct mlx5_esw_bridge_port that is used to store
metadata for all port vlans. Initialize and cleanup the instance of the
structure when port representor is linked/unliked to bridge. Use xarray to
allow quick vport metadata lookup by vport number.

- Add new per-port-vlan struct mlx5_esw_bridge_vlan that is used to store
vlan-specific data (vid, flags). Handle SWITCHDEV_PORT_OBJ_{ADD|DEL}
switchdev blocking event for SWITCHDEV_OBJ_ID_PORT_VLAN object by
creating/deleting the vlan structure and saving it in per-vport xarray for
quick lookup.

- Implement support for SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING object
attribute that is used to toggle vlan filtering. Remove all FDB entries
from hardware when vlan filtering state is changed.

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Jianbo Liu <jianbol@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>