nfp: update maintainer and mailing list addresses

Some of Netronome's activities and people have moved over to Corigine,
including NFP driver maintenance and myself.

Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>