[SCSI] qla2xxx: prep for fc host dev loss tmo support

This removes the driver's get_host_def_dev_loss_tmo
callback and just has the driver set the dev loss
using the fc class fc_host_dev_loss_tmo macro like is
done for other fc params.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>