crypto: sun8i-ce - use helpers to get hash block and digest sizes

Use crypto_ahash_blocksize() and crypto_ahash_digestsize() helpers instead
of directly accessing 'struct ahash_alg' members.

Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>