Replace direct calls to power supply function attributes with wrappers.
Wrappers provide safe access in case of unregistering the power
supply (e.g. by removing the driver). Replace:
- get_property -> power_supply_get_property
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Reviewed-by: Sebastian Reichel <sre@kernel.org> Signed-off-by: Sebastian Reichel <sre@kernel.org>