net/mlx5: E-Switch, Indirect table infrastructure

Indirect table infrastructure is used to allow fully processing VF tunnel
traffic in hardware. Kernel software model uses two TC rules for such
traffic: UL rep to tunnel device, then tunnel VF rep to destination VF rep.
To implement such pipeline driver needs to program the hardware after
matching on UL rule to overwrite source vport from UL to tunnel VF and
recirculate the packet to the root table to allow matching on the rule
installed on tunnel VF. For this indirect table matches all encapsulated
traffic by tunnel parameters and all other IP traffic is sent to tunnel VF
by the miss rule.

Indirect table API overview:

- mlx5_esw_indir_table_{init|destroy}() - init and destroy opaque indirect
table object.

- mlx5_esw_indir_table_get() - get or create new table according to vport
id and IP version. Table has following pre-created groups: recirculation
group with match on ethertype and VNI (rules that match encapsulated
packets are installed to this group) and forward group with default/miss
rule that forwards to vport of tunnel endpoint VF (rule for regular
non-encapsulated packets).

- mlx5_esw_indir_table_put() - decrease reference to the indirect table and
matching rule (for encapsulated traffic).

- mlx5_esw_indir_table_needed() - check that in_port is an uplink port and
out_port is VF on the same eswitch, verify that the rule is for IP traffic
and source port rewrite functionality can be used.

- mlx5_esw_indir_table_decap_vport() - function returns decap vport of
flow attribute.

Co-developed-by: Dmytro Linkin <dlinkin@nvidia.com>
Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>