ifxhcd never had roothub support but since kernel 3.x it was expected
that a roothub always exists.
The patched fixed a null pointer deref in the usb subsystem because of
the missing roothub.
Since ifxhcd is gone, this whole patch isn't required any longer.
Signed-off-by: Mathias Kresin <dev@kresin.me>
c0e66478b5