Merge tag 'usb-serial-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/johan...

Johan writes:

USB-serial updates for v4.4-rc1

These updates generalise the option DTR/RTS handling so that all
usb-wwan-based drivers can use it. This is specifically needed by some
Sierra modems, which can now all be handled by qcserial again.

Included are also some clean ups of the io_ti firmware handling.

Signed-off-by: Johan Hovold <johan@kernel.org>