All ports are disabled by default, so configure the port isolation masks
and the pm field accordingly in the setup function. When port_enable is
called for a port, the isolation masks will be set up so that traffic
can flow between the port and the CPU.
While at it, change the code to also use the traffic_set method in
rtl83xx_setup, instead of writing to the RTL838x_PORT_ISO_CTRL(i)
registers directly.
Signed-off-by: Jan Hoffmann <jan@3e8.eu>