net/mlx5e: TC, map tc action cookie to a hw counter

Currently a hardware counter is associated with a flow cookie.
This does not apply to flows using branching action which are required to
return per action stats.

A single counter may apply to multiple actions.
Scan the flow actions in reverse (from the last to the first action) while
caching the last counter.
Associate all the flow attribute tc action cookies with the current
cached counter.

Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>