Merge tag 'usb-for-v4.9' of git:// into usb-next

Felipe writes:

usb: patches for v4.9 merge window

This time around we have 92 non-merge commits. Most
of the changes are in drivers/usb/gadget (40.3%)
with drivers/usb/gadget/function being the most
active directory (27.2%).

As for UDC drivers, only dwc3 (26.5%) and dwc2
(12.7%) have really been active.

The most important changes for dwc3 are better
support for scatterlist and, again, throughput
improvements. While on dwc2 got some minor stability
fixes related to soft reset and FIFO usage.

Felipe Tonello has done some good work fixing up our
f_midi gadget and Tal Shorer has implemented a nice
API change for our ULPI bus.

Apart from these, we have our usual set of
non-critical fixes, spelling fixes, build warning
fixes, etc.