net/mlx5e: Enable multi-queue and RSS for VF representors

Increased the amount of channels the representors can open to be the
amount of CPUs. The default amount opened remains one.

Used the standard NIC netdev functions to:
* Set RSS params when building the representors' params.
* Setup an indirect TIR and RQT for the representors upon
  initialization.
* Create a TTC flow table for the representors' indirect TIR (when
  creating the TTC table, mlx5e_set_ttc_basic_params() is not called,
  in order to avoid setting the inner_ttc param, which is not needed).

Added ethtool control to the representors for setting and querying
the amount of open channels. Additionally, included logic in the
representors' ethtool set channels handler which controls a
representor's vport rx rule, so that if there is one open channel
the rx rule steers traffic to the representor's direct TIR, whereas
if there is more than one channel, the rx rule steers traffic to the
new TTC flow table.

Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>