net: mscc: ocelot: limit vlan ingress filtering to actual number of ports

The VSC7514 switch (Ocelot) is a 10-port device, while VSC9959 (Felix)
is 6-port. Therefore the VLAN filtering mask would be out of bounds when
calling for this new switch. Fix that.

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