crypto: mxs - Add Freescale MXS DCP driver

Add support for the MXS DCP block. The driver currently supports
SHA-1/SHA-256 hashing and AES-128 CBC/ECB modes. The non-standard
CRC32 is not yet supported.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>