ionic: add rx filtering for hw timestamp steering

Add handling of the new Rx packet classification filter type.
This simple bit of classification allows for steering packets
to a separate Rx queue for processing.

Signed-off-by: Allen Hubbe <allenbh@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>