dm: usb: Complete the splitting up of usb_new_device()

This function now calls usb_setup_device() to set up the device and
usb_hub_probe() to check if it is a hub. The XHCI special case is now a
parameter to usb_setup_device(). The latter will be used by the USB uclass
when it is added, since it does not rely on any CONFIGs or legacy data
structures.

Signed-off-by: Simon Glass <sjg@chromium.org>
Bug-fixes for descriptor reading and usb_new_device() return value
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Tested-by: Tom Rini <trini@konsulko.com>