proc_usb_info.txt: Correct documentation about endianness of config descriptors

The config descriptors as read from /proc/bus/usb/BBB/DDD are in *bus* endian
format. Correct proc_usb_info.txt to correctly reflect that.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>