[PATCH] driver core: Add the ability to unbind drivers to devices from userspace

This adds a single file, "unbind", to the sysfs directory of every
device that is currently bound to a driver.  To unbind the driver from
the device, write anything to this file and they will be disconnected
from each other.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>