sfc: support offloading ct(nat) action in RHS rules

If an IP address and/or L4 port for NAPT is available from a CT match,
 the MAE will perform the edits; if no CT lookup has been performed for
 this packet, the CT lookup did not return a match, or the matched CT
 entry did not include NAPT, the action will have no effect.

Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>