net/mlx5: SF, Implement peer devlink set for SF representor devlink port

net/mlx5: SF, Implement peer devlink set for SF representor devlink port

Benefit from the existence of internal mlx5 notifier and extend it by
event MLX5_DRIVER_EVENT_SF_PEER_DEVLINK. Use this event from SF
auxiliary device probe/remove functions to pass the registered SF
devlink instance to the SF representor.

Process the new event in SF representor code and call
devl_port_fn_devlink_set() to do the assignments. Implement this in work
to avoid possible deadlock when probe/remove function of SF may be
called with devlink instance lock held during devlink reload.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>