net: dsa: rzn1-a5psw: remove redundant logs

Remove debug logs in port vlan management, since there are already multiple
tracepoints defined for those operations in DSA

Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>