power: supply: axp288_charger: Some minor cleanups

Remove info->health, info->present and info->online caching, as no code
is reading the cached values.

Remove if (changed) check before calling power_supply_changed(), we
return early from axp288_charger_extcon_evt_worker if nothing has
changed, so the check is not needed.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>