If userspace only reads the trackstick node, and no one is listening to
the touchpad nor the hidraw node then, the device is not powered on.

Add open/close callbacks to allow users to disable the touchpad in Gnome
while keeping the trackstick active.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1559632
Link: https://gitlab.gnome.org/GNOME/mutter/issues/128Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>