[SCSI] zfcp: enable FCP hardware data router by default

Enabling the data router support by default
can increase performance in certain situations.
It is safe to do so and tolerated in LPAR and under z/VM
in case there is no data router support in that environment.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>