crypto: safexcel/aes - switch to library version of key expansion routine

Switch to the new AES library that also provides an implementation of
the AES key expansion routine. This removes the dependency on the
generic AES cipher, allowing it to be omitted entirely in the future.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>