libpayload: Port usb hub driver to use the generic code

This is mostly a rewrite, don't even try to read a diff.

Tested with an internal rate matching hub on a QM77 board and three hubs
integrated into DELL monitors.

Change-Id: Ib12fa2aa90af4e0f37143d2ed92c4a1705b6d774
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3451
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2 files changed