mlxsw: spectrum: Switch to VID 4095 as default VID

There is no need to abuse VID 1 anymore and we can instead use VID 4095
as the default VLAN, which will be configured on the port throughout its
lifetime.

The OVS join / leave functions are changed to enable VIDs 1-4094
(inclusive) instead of 2-4095. This because VID 4095 is now the default
VLAN instead of 1.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>