acl: fix build and runtime for default target

acl: fix build and runtime for default target

Make ACL library to build/work on 'default' architecture:
- make rte_acl_classify_scalar really scalar
 (make sure it wouldn't use sse4 instrincts through resolve_priority()).
- Provide two versions of rte_acl_classify code path:
  rte_acl_classify_sse() - could be build and used only on systems with sse4.2
  and upper, return -ENOTSUP on lower arch.
  rte_acl_classify_scalar() - a slower version, but could be build and used
  on all systems.
- Addition of a new function rte_acl_classify_alg.  This function lets you
  specify an enum value to override the acl contexts default algorithm when doing
  a classification.  This allows an application to specify a classification
  algorithm without needing to publicize each method. I know there was concern
  over keeping those methods public, but we don't have a static ABI at the moment,
  so this seems to me a reasonable thing to do, as it gives us less of an ABI
  surface to worry about.
- keep common code shared between these two codepaths.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>