usbdebug: Support i82801dx/ex southbridge

Tested on i82801dx system with board aopen/dxplplusu.

Change-Id: I522455ac79c87b9b6fc9cd8c4dc0da3563dfbfad
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3381
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
4 files changed