[SCSI] zfcp: Report fc_host_port_type as NPIV

Report the fc_host_port_type as FC_PORTTYPE_NPIV when the subchannel
is running in NPIV mode. This allows to see the correct type with
lsscsi -H -t --list

Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>