crypto: sunxi-ss - Add Allwinner Security System crypto accelerator

Add support for the Security System included in Allwinner SoC A20.
The Security System is a hardware cryptographic accelerator that support:
- MD5 and SHA1 hash algorithms
- AES block cipher in CBC/ECB mode with 128/196/256bits keys.
- DES and 3DES block cipher in CBC/ECB mode

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>