power_supply: bq2415x_charger: Add ACPI support

Replace of_property_read_u32() with device_property_read_u32(), which is a
wrapper over ACPI and device tree enumeration methods.
When ACPI enumeration is used, automode is not supported. Therefore,
bq2415x_charger does not update its input current automatically, depending
on the USB port type that is connected to. Input current may be updated via
sysfs.

Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>