crypto: provide single place for hash algo information

This patch provides a single place for information about hash algorithms,
such as hash sizes and kernel driver names, which will be used by IMA
and the public key code.

Changelog:
- Fix sparse and checkpatch warnings
- Move hash algo enums to uapi for userspace signing functions.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>