HID: usbhid: add always-poll quirk

Add quirk to make sure that a device is always polled for input events
even if it hasn't been opened.

This is needed for devices that disconnects from the bus unless the
interrupt endpoint has been polled at least once or when not responding
to an input event (e.g. after having shut down X).

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>