Convert the SSE2 implementation of Serpent from the (deprecated)
ablkcipher and blkcipher interfaces over to the skcipher interface.
Note that this includes replacing the use of ablk_helper with
crypto_simd.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>