Documentation usb serial: fixed how to provide vendor and product id
While trying to test a Cinterion GSM/GPS/3G module I had reconfigured
the USB interface by mistake and therefore needed to run a different
USB driver than CDC-ACM. It turned out that I need the "usbserial" driver.
This file is an official description how to use it:
Documentation/usb/usb-serial.txt
But it is outdated. The parameters vendor= and product= have been
superseded by a /sys interface.
This patch changes the documentation file to describe the modern variant.
Please note that the old one still works (if compiled as module).
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com> Signed-off-by: Marek Belisko <marek@goldelico.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>