[SCSI] IB/iSER: add logical unit reset support

eh_device_reset_handler was already added to scsi_host_template
in iscsi_tcp, and is now added also for iscsi_iser.

Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>