crypto: crypto4xx - fix blocksize for cfb and ofb

While the hardware consider them to be blockciphers, the
reference implementation defines them as streamciphers.

Do the right thing and set the blocksize to 1. This
was found by CONFIG_CRYPTO_MANAGER_EXTRA_TESTS.

This fixes the following issues:
skcipher: blocksize for ofb-aes-ppc4xx (16) doesn't match generic impl (1)
skcipher: blocksize for cfb-aes-ppc4xx (16) doesn't match generic impl (1)

Cc: Eric Biggers <ebiggers@kernel.org>
Cc: stable@vger.kernel.org
Fixes: f2a13e7c ("crypto: crypto4xx - enable AES RFC3686, ECB, CFB and OFB offloads")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>