power: supply: cw2015: Use device managed API to simplify the code

Use devm_delayed_work_autocancel() instead of the INIT_DELAYED_WORK() to
remove the cw_bat_remove() function.

And power_supply_put_battery_info() can also be removed because the
power_supply_get_battery_info() uses device managed memory allocation.

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>