Merge branch 'mlxsw-support-for-nexthop-group-statistics'

Petr Machata says:

====================
mlxsw: Support for nexthop group statistics

ECMP is a fundamental component in L3 designs. However, it's fragile. Many
factors influence whether an ECMP group will operate as intended: hash
policy (i.e. the set of fields that contribute to ECMP hash calculation),
neighbor validity, hash seed (which might lead to polarization) or the type
of ECMP group used (hash-threshold or resilient).

At the same time, collection of statistics that would help an operator
determine that the group performs as desired, is difficult.

Support for nexthop group statistics and their HW collection has been
introduced recently. In this patch set, add HW stats collection support
to mlxsw.

This patchset progresses as follows:

- Patches #1 and #2 add nexthop IDs to notifiers.
- Patches #3 and #4 are code-shaping.
- Patches #5, #6 and #7 adjust the flow counter code.
- Patches #8 and #9 add HW nexthop counters.
- Patch #10 adjusts the HW counter code to allow sharing the same counter
  for several resilient group buckets with the same NH ID.
- Patch #11 adds a selftest.
====================

Link: https://lore.kernel.org/r/cover.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>