Add initial D-Link DIR-655 (A1) support.

This is based on the AP135 design - QCA9558 SoC, 3x3 2GHz wifi, but no
5GHz (11n or 11ac) chip is available.

It however still has 128MiB of RAM, 16MiB of NOR flash and the AR8327N
gigabit switch - so it's quite a beefy router device.

Tested:

• Well, a unit, naturally

Obtained from: Completely messing up an amazon.com order and getting this instead, and asking "hey, wonder if I could.."