HID: sony: Ignore DS4 dongle reports when no device is connected

When the DS4 dongle is connected, it always generates HID reports
even when no DS4 is paired to it. This patch adds logic to ignore
HID reports from the dongle if there is no DS4 currently attached.

Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>