crypto: sun4i-ss - checking sg length is not sufficient

commit 7bdcd851fa7eb66e8922aa7f6cba9e2f2427a7cf upstream.

The optimized cipher function need length multiple of 4 bytes.
But it get sometimes odd length.
This is due to SG data could be stored with an offset.

So the fix is to check also if the offset is aligned with 4 bytes.
Fixes: 6298e948 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Cc: <stable@vger.kernel.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>