This replaces the scalar AES cipher that originates in the OpenSSL project
with a new implementation that is ~15% (*) faster (on modern cores), and
reuses the lookup tables and the key schedule generation routines from the
generic C implementation (which is usually compiled in anyway due to
networking and other subsystems depending on it).

Note that the bit sliced NEON code for AES still depends on the scalar cipher
that this patch replaces, so it is not removed entirely yet.

* On Cortex-A57, the performance increases from 17.0 to 14.9 cycles per byte
  for 128-bit keys.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>