ocelot_ace: fix action of trap

The trap action should be copying the frame to CPU and
dropping it for forwarding, but current setting was just
copying frame to CPU.

Fixes: b5962294 ("net: mscc: ocelot: Add support for tcam")
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Allan W. Nielsen <allan.nielsen@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>