crypto: marvell - Don't hardcode block size in mv_cesa_ahash_cache_req

Don't use 64 'as is', as max block size in mv_cesa_ahash_cache_req. Use
CESA_MAX_HASH_BLOCK_SIZE instead, this is better for readability.

Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>