crypto: sa2ul - add sha1/sha256/sha512 support

Add support for sha1/sha256/sha512 sa2ul based hardware authentication.
With the hash update mechanism, we always use software fallback
mechanism for now, as there is no way to fetch the partial hash state
from the HW accelerator. HW accelerator is only used when digest is
called for a data chunk of known size.

Signed-off-by: Keerthy <j-keerthy@ti.com>
[t-kristo@ti.com: various bug fixes, major cleanups and refactoring of code]
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>