mlxsw: reg: Add Switch Port VID and Switch Port VLAN Membership registers definitions

Add SPVID and SPVM registers responsible for default port VID
configuration and VLAN membership of a port.

Signed-off-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>