Merge branch 'marvell-prestera-devlink'

Oleksandr Mazur says:

====================
Marvell Prestera driver implementation of devlink functionality.

This patch series implement Prestera Switchdev driver devlink traps,
that are registered within the driver, as well as extend current devlink
functionality by adding new hard drop statistics counter, that could be
retrieved on-demand: the counter shows number of packets that have been
dropped by the underlying device and haven't been passed to the devlink
subsystem.

The core prestera-devlink functionality is implemented in the prestera_devlink.c.

The patch series also extends the existing devlink kernel API:
 - devlink: add trap_drop_counter_get callback for driver to register - make it possible
   to keep track of how many packets have been dropped (hard) by the switch device, before
   the packets even made it to the devlink subsystem (e.g. dropped due to RXDMA buffer
   overflow).

The core features that extend current functionality of prestera Switchdev driver:
 - add logic for driver traps and drops registration (also traps with DROP action).
 - add documentation for prestera driver traps and drops group.

PATCH v2:
 1) Rebase whole series on top of latest mater;
 2) Remove storm control-related patches, as they're out of devlink
    scope;
====================

Signed-off-by: David S. Miller <davem@davemloft.net>