net: dsa: mv88e6xxx: add call to mv88e6xxx_ports_cmode_init to probe for new DSA framework

In the original patch I missed to add mv88e6xxx_ports_cmode_init()
to the second probe function, the one for the new DSA framework.

Fixes: ed8fe202

 ("net: dsa: mv88e6xxx: prevent interrupt storm caused by mv88e6390x_port_set_cmode")
Reported-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>