crypto: sha1-ssse3 - Disable avx2

It has been reported that sha1-avx2 can cause page faults by reading
beyond the end of the input.  This patch disables it until it can be
fixed.

Cc: <stable@vger.kernel.org>
Fixes: 7c1da8d0

 ("crypto: sha - SHA1 transform x86_64 AVX2")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>