With !155, the device bus ID received via udev is constructed
properly with the "usb:" prefix. But, it is not enough to
make the following line to work in Section "Device":
BusID "usb:0:1.2:1.0"
Introduce BUS_USB, so the prefix can be distinguished from BUS_PCI
and check the supplied BusID value against device->attribs->busid
in xf86PlatformDeviceCheckBusID().
Signed-off-by: Böszörményi Zoltán <zboszor@pr.hu>
682167475c