[SCSI] libfc: Add local port point-to-multipoint flag

For VN_port to VN_port mode, the transport sets the port_id and
there's no lport FLOGI.  This is similar to FC loop mode.

Add a point_to_multipoint flag that indicates the local port is in
point-to-multipoint mode.  This skips FLOGI and discovery.
It also skips resetting the port_id on resets other than link down.

Add function fc_lport_set_local_id() that sets the local port_id.
This is called by libfcoe on behalf of the low-level driver
to set the port_id when the link comes up.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>