crypto: sun4i-ss - fix big endian issues

When testing BigEndian kernel, the sun4i-ss was failling all crypto
tests.
This patch fix endian issues with it.

Fixes: 6298e948 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>