crypto: sahara - add support for SHA1/256

Add support for the MDHA unit in the SAHARA core.
The MDHA can generate hash digests for MD5 and SHA1 in version 3 and
additionally SHA224 and SHA256 in version 4.

Add the SHA1 and SHA256 algorithms to the driver.

The implementation was tested with the in-kernel testmgr and a userspace
testprogram using AF_ALG with+without upto 128 pthreads on each AES and
SHA256 on i.MX53.
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>