net/mlx5e: Re-attempt to offload flows on multipath port affinity events

Under multipath it's possible for us to offload the flow only through
the e-switch for which proper route through the uplink exists.
When the port is up and the next-hop route is set again we want to
offload through it as well.

We generate SW event from the FIB event handler when multipath port
affinity changes. The tc offloads code gets this event, goes over the
flows which were marked as of having missing route and attempts to
offload them.

Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>