Merge branch 'ovs_hash'

Francesco Fusco says:

====================
ovs: introduce arch-specific fast hashing improvements

From: Daniel Borkmann <[email protected]>

We are introducing a fast hash function (see patch1) that can be
used in the context of OpenVSwitch to reduce the hashing footprint
(patch2). For details, please see individual patches!

v1->v2:
 - Make hash generic and place it under lib
====================

Signed-off-by: David S. Miller <[email protected]>