net: sparx5: add port mirroring implementation

The hardware supports three independent mirroring probes. Each probe can
be configured to mirror rx or tx traffic (direction).

Using tc matchall, it is now possible to add a source port and a monitor
port to a mirror probe. Depending on the mirror direction, rx or tx
traffic from a source port will be mirrored to the monitor port.

A single source port can be a member of multiple mirror probes.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>