This adds the CPU port to the unknown multicast flooding port mask,
which fixes the VLAN issues introduced by the multicast group patches
Tested-by: Russell Senior <russell@personaltelco.net> [Netgear GS108Tv3]
Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no> [whitespace fix]
Signed-off-by: Petr Štetiar <ynezz@true.cz> [unknwon typo fix]