HID: logitech-dj: enable notifications on connect/disconnect

The receiver can send HID++ notifications to the DJ devices when the
physical devices are connected/disconnected.
Enable this feature by default.

This command uses a HID++ command instead of a DJ one, so use a direct
call to usbhid instead of using logi_dj_recv_send_report()

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>