This is (almost!) enough to actually probe, attach, configure a default
port group and do some basic work. It's also totally hard-coded for
the Qualcomm Atheros DB120 board - it doesn't yet have any of the code
from OpenWRT which parses extra configuration data to know how to program
the switch. The LED stuff is also missing.
But, it's enough to facilitate board, PHY, switch and VLAN bringup,
so I am committing it now.
Tested:
* Qualcomm Atheros DB120
Obtained from: OpenWRT
7330dd0bb4