crypto: aegis128l/aegis256 - remove x86 and generic implementations

Three variants of AEGIS were proposed for the CAESAR competition, and
only one was selected for the final portfolio: AEGIS128.

The other variants, AEGIS128L and AEGIS256, are not likely to ever turn
up in networking protocols or other places where interoperability
between Linux and other systems is a concern, nor are they likely to
be subjected to further cryptanalysis. However, uninformed users may
think that AEGIS128L (which is faster) is equally fit for use.

So let's remove them now, before anyone starts using them and we are
forced to support them forever.

Note that there are no known flaws in the algorithms or in any of these
implementations, but they have simply outlived their usefulness.

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>