net/mlx5: prepare support for RSS action rule
net/mlx5: prepare support for RSS action rule

In mlx5 PMD handling a single queue of several destination queues ends in
creating the same Verbs attribute, the main difference resides in the
indirection table and the RSS hash key.

This helps to prepare the supports to the RSS queues by first handling the
queue action has being an RSS queue with a single queue.  No RSS hash key
will be provided to the Verbs flow.

Signed-off-by: Nelio Laranjeiro <2f8dd9032d5b85ca4b53dec8ce664eb6998836be@6wind.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk