cciss: Make device attributes static

Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>