usbhub.sys: add stubbed usbhub.sys

[Alexandre Julliard]

Damjan Jovanovic <damjan.jov at gmail.com> writes:

> usbhub.sys isn't accessed via exports and I don't think anything
> depends on usbhub.sys specifically - but on Windows it builds device
> objects for USB devices and does I/O to these, so it seems like the
> best place to do those in Wine too.

I'm not convinced that splitting this stuff across modules is a good
idea. There isn't much reason to replicate the Windows I/O stack layout
because our devices work quite differently.

-- 
Alexandre Julliard
julliard at winehq.org