crypto: sha512-mb - SHA512 multibuffer job manager and glue code

This patch introduces the multi-buffer job manager which is responsible
for submitting scatter-gather buffers from several SHA512 jobs to the
multi-buffer algorithm. It also contains the flush routine that's called
by the crypto daemon to complete the job when no new jobs arrive before
the deadline of maximum latency of a SHA512 crypto job.

The SHA512 multi-buffer crypto algorithm is defined and initialized in this
patch.

Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>