crypto: sahara - fix building as module

The sahara crypto driver has an incorrect MODULE_DEVICE_TABLE, which
prevents us from actually building this driver as a loadable module.

sahara_dt_ids is a of_device_id array, so we have to use
MODULE_DEVICE_TABLE(of, ...).

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>