doc: bindings: power: act8945a-charger: Update properties.

Due the driver improvements, update the properties,
 - Remove "active-semi,check-battery-temperature" property.
 - Add the properties, "active-semi,irq_gpio"
   and "active-semi,lbo-gpios".
 - As act8945a-charger is regarded as a sub-device, update
   the compatible and examples.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>