crypto: qat - fix aes-xts key sizes

Increase value of supported key sizes for qat_aes_xts.
aes-xts keys consists of keys of equal size concatenated.

Fixes: def14bfa

 ("crypto: qat - add support for ctr(aes) and xts(aes)")
Cc: stable@vger.kernel.org
Reported-by: Wenqian Yu <wenqian.yu@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>