cciss: select CONFIG_CHECK_SIGNATURE

The patch cciss-use-check_signature.patch in -mm tree introduced
a build error:

drivers/built-in.o: In function `CISS_signature_present':
drivers/block/cciss.c:4270: undefined reference to `check_signature'

Add missing CONFIG_CHECK_SIGNATURE to fix this issue.

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Fengguang Wu <wfg@linux.intel.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Acked-by: "Stephen M. Cameron" <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>