Add some plumbing to allow the AEGIS128 code to be built with SIMD
routines for acceleration.
Reviewed-by: NOndrej Mosnacek <omosnace@redhat.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>