crypto: mxs-dcp - fix scatterlist linearization for hash

commit fa03481b upstream.

The incorrect traversal of the scatterlist, during the linearization phase
lead to computing the hash value of the wrong input buffer.
New implementation uses scatterwalk_map_and_copy()
to address this issue.

Cc: <stable@vger.kernel.org>
Fixes: 15b59e7c ("crypto: mxs - Add Freescale MXS DCP driver")
Signed-off-by: Rosioru Dragos <dragos.rosioru@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>