net/mlx5: change hairpin ingress flow validation

net/mlx5: change hairpin ingress flow validation

In the current implementation of the single port hairpin, there is
an implicit splitting process for actions. When inserting a hairpin
flow, all the actions will be included with the ingress attribute.
The flow engine will check and decide which actions should be moved
into the TX flow part, e.g., encapsulation, VLAN push.

In some NICs, some actions can only be done in one direction. Since
the hairpin flow will be split into two parts, such validation will
be skipped.

With the hairpin explicit TX flow mode, no splitting is needed any
more. The hairpin flow may have no big difference from a standard
flow (except the queue). The application should take full charge of
the actions and the flow engine should validate the hairpin flow in
the same way as other flows.

In the meanwhile, a new internal API is added to get the hairpin
configuration. This will bypass the useless atomic operation to save
the CPU cycles.

Signed-off-by: Bing Zhao <bingz@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>