usbhid tries to give the device 50 milliseconds to drain its queues when
opening the device, but does it naively by simply sleeping in open handler,
which slows down device probing (and thus may affect overall boot time).

However we do not need to sleep as we can instead mark a point of time in
the future when we should start processing the events.
Reported-by: NNicolas Boichat <drinkcat@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: NGuenter Roeck <groeck@chromium.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>