Add the charger status change interrupt support, it will report
the power supply changed event.

This interrupt is generated by one of the conditions as below:
 - the state machine jumps out of or into the EOC state
 - the CHGIN input voltage goes out of or into the valid range.
 - the battery temperature goes out of or into the valid range.
 - the PRECHARGE time-out occurs.
 - the total charge time-out occurs.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>