crypto: sha-mb - SHA1 multibuffer crypto computation (x8 AVX2)

This patch introduces the assembly routines to do SHA1 computation on
buffers belonging to serveral jobs at once.  The assembly routines are
optimized with AVX2 instructions that have 8 data lanes and using AVX2
registers.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>