net: dsa: rtl8366: Check VLAN ID and not ports

There has been some confusion between the port number and
the VLAN ID in this driver. What we need to check for
validity is the VLAN ID, nothing else.

The current confusion came from assigning a few default
VLANs for default routing and we need to rewrite that
properly.

Instead of checking if the port number is a valid VLAN
ID, check the actual VLAN IDs passed in to the callback
one by one as expected.

Fixes: d8652956

 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>