Provide an accelerated implementation of aegis128 by wiring up the
SIMD hooks in the generic driver to an implementation based on NEON
intrinsics, which can be compiled to both ARM and arm64 code.

This results in a performance of 2.2 cycles per byte on Cortex-A53,
which is a performance increase of ~11x compared to the generic
code.
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>