crypto: engine - permit to enqueue ashash_request

The current crypto engine allow only ablkcipher_request to be enqueued.
Thus denying any use of it for hardware that also handle hash algo.

This patch modify the API for allowing to enqueue ciphers and hash.

Since omap-aes/omap-des are the only users, this patch also convert them
to the new cryptoengine API.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>