ice: switchdev slow path

Slow path means allowing packet to go from uplink to representor
and from representor to correct VF on Rx site and from VF to
representor and to uplink on Tx site.

To accomplish this driver, has to set correct Tx descriptor. When
packet is sent from representor to VF, destination should be
set to VF VSI. When packet is sent from uplink port destination
should be uplink to bypass switch infrastructure and send packet
outside.

On Rx site driver should check source VSI field from Rx descriptor
and based on that forward packed to correct netdev. To allow
this there is a target netdevs table in control plane VSI
struct.

Co-developed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>