net: dsa: mv88e6xxx: map destination addresses for 6185

net: dsa: mv88e6xxx: map destination addresses for 6185

The 88E6185 switch also has a MapDA bit in its Port Control 2 register.
When this bit is cleared, all frames are sent out to the CPU port.

Set this bit to rely on address databases (ATU) hits and direct frames
out of the correct ports, and thus allow hardware bridging.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>