[SCSI] fc transport: add permanent_port_name fc_host attribute

Add fc_host attribute permanent_port_name which is
used to show the port name of the primary port -
the port that initially logged into the fabric.

For a virtual port (registered via the primary port with
FDISC command) it is useful to know not only its (virtual)
port name but also the permanent port name.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>