net/enic: enable limited RSS flow action

net/enic: enable limited RSS flow action

Some apps like OVS-DPDK use MARK+RSS flow rules in order to offload
packet matching to the NIC. The RSS action in such flow rules simply
indicates "receive packet normally", not trying to override the port
wide RSS. The action is included in the flow rules simply to terminate
them, as MARK is not a fate-deciding action. And, the RSS action has a
most basic config: default hash, level, types, null key, and identity
queue mapping.

Recent VIC adapters can support these "mark and receive" flow
rules. So, enable support for RSS action for this limited use case.

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@cisco.com>