gemini: Bring up DSA switches

gemini: Bring up DSA switches

First group the interfaces on the DSA switch into the
right LAN/WAN groups. Tested successfully on the
D-Link DIR-685 with the RTL8366RB DSA switch.

The RTL8366RB is DSA custom tagged and now handled
by the kernel tag parser. (Backported.)

The Vitesse switches are not capable of supporting
DSA per-port tagging. We suspect they must be handled
using some custom VLAN set-up.

Cc: Pawel Dembicki <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
[sorted devices alphabetically]
Signed-off-by: Christian Lamparter <[email protected]>