net/mlx5e: TC, support per action stats

Extend the action stats callback implementation to update stats for actions
that are associated with hw counters.
Note that the callback may be called from tc action utility or from tc
flower. Both apis expect the driver to return the stats difference from
the last update. As such, query the raw counter value and maintain
the diff from the last api call in the tc layer, instead of the fs_core
layer.

Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>