power: supply: axp288_charger: Make charger_init_hw_regs propagate i2c errors

Make charger_init_hw_regs propagate i2c errors, instead of only warning
about them and then ignoring them.

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