net: dsa: seville: fix VCAP IS2 action width

Since the actions are packed together in the action RAM, an incorrect
action width means that no action except the first one would behave
correctly.

The tc-flower offload has probably not been tested on this hardware
since its introduction.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>