rtc: rtc-sun4v fixes, revised
- simplified code
- use platform_driver_probe
- removed locking: it's provided by rtc subsystem
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: David S. Miller <davem@davemloft.net>
authored by Alessandro Zummo and committed by David S. Miller cecf61bd e64ed022