The DualShock 4 dongle isn't connected to a real DualShock 4 at
time of driver loading. When a DualShock 4 is plugged in, we
need to obtain calibration data (the dongle would have zeros).

This patch adds calibration logic, which we schedule on a hotplug
from sony_raw_event. In addition this patch adds dongle state
handling.
Signed-off-by: NRoderick Colenbrander <roderick.colenbrander@sony.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>