net/enic: update UDP RSS controls

Current adapters which support UDP RSS piggyback on TCP RSS. Change
the controls to be forward compatible with future adapters, which will
have independent control of UDP and TCP.

Fixes: 9bd04182bb01 ("net/enic: support UDP RSS on 1400 series adapters")

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