rtl83xx: dsa: reset PVID to 1 instead of 0

rtl83xx: dsa: reset PVID to 1 instead of 0

Before, PVID is reset for all ports and goes out of bounds. Also, PVID
is later changed by dsa configuration by `ip link` and `bridge vlan`
commands, this does not change the CPU port PVID and CPU PVID stays 0.
It does not allow sending packets from OpenWrt to any connected devices
unless default configuration is changed

This change iterates up to and including cpu_port and sets default PVID
to 1. For lan* ports PVID can be configured with `ip link` and `bridge
vlan` commands

Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Harshal Gohel <hg@simonwunderlich.de>