[SCSI] zfcp: add additional fc_host attributes

this patch adds some fc host attributes and removes its equivalents
from the zfcp_adapter structure and zfcp specific sysfs subtree.

Furthermore it removes superfluous calls to fc_remort_port_delete when
an adapter is set offline because rports will be removed by
fc_remove_host anyway.

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