nfp: spawn nfp_ports for PF and VF ports

nfp_port is an abstraction which is supposed to allow us sharing
code between different netdev types (vNIC vs repr).  Spawn ports
for PFs and VFs to enable this sharing.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>