power: supply: axp288_charger: Support 3500 and 4000 mA input current limit

The AXP288 supports an input-current-limit of up to 4000 mA, this
commit adds support for the 3500 and 4000 mA settings which were
missing until now.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>