This includes adding support for skipping FTDI interfaces used for JTAG
leaving them for userland and just attaching to the RS232 half, similarly
to how the corresponding Linux drivers handles these kind of adapters.
While at it, sort uftdi_devs and return BUS_PROBE_SPECIFIC (because
uftdi_probe() alters the instance variables for better or worse as do
other probe routines of USB drivers) instead of 0.
- Remove duplicated entries for BeagleBone.
- Use DEVMETHOD_END.
- Use NULL instead of 0 for pointers.
- Remove some stray lines.
MFC after: 3 days
a589806b07