power: axp288_fuel_gauge: Constify platform_device_id

The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/axp288_fuel_gauge.c

···
 	return ret;
 }
 
-static struct platform_device_id axp288_fg_id_table[] = {
+static const struct platform_device_id axp288_fg_id_table[] = {
 	{ .name = DEV_NAME },
 	{},
 };