net: ethernet: ti: cpsw: fix allmulti cfg in dual_mac mode

Now CPSW ALE will set/clean Host port bit in Unregistered Multicast Flood
Mask (UNREG_MCAST_FLOOD_MASK) for every VLAN without checking if this port
belongs to VLAN or not when ALLMULTI mode flag is set for nedev. This is
working in non dual_mac mode, but in dual_mac - it causes
enabling/disabling ALLMULTI flag for both ports.

Hence fix it by adding additional parameter to cpsw_ale_set_allmulti() to
specify ALE port number for which ALLMULTI has to be enabled and check if
port belongs to VLAN before modifying UNREG_MCAST_FLOOD_MASK.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>