crypto: blake2s - remove shash module

BLAKE2s has no currently known use as an shash. Just remove all of this
unnecessary plumbing. Removing this shash was something we talked about
back when we were making BLAKE2s a built-in, but I simply never got
around to doing it. So this completes that project.

Importantly, this fixs a bug in which the lib code depends on
crypto_simd_disabled_for_test, causing linker errors.

Also add more alignment tests to the selftests and compare SIMD and
non-SIMD compression functions, to make up for what we lose from
testmgr.c.

Reported-by: gaochao <gaochao49@huawei.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 6048fdcc

 ("lib/crypto: blake2s: include as built-in")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>