zfcp: add point-2-point support

From: Andreas Herrmann <aherrman@de.ibm.com>

This patch mainly introduces support for point-2-point
topology.

From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Maxim Shchetynin <maxim@de.ibm.com>
From: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>