power: supply: axp288_fuel_gauge: Remove unnecessary irq?_en register writes

Setting the irq_enable bits is taken care of by the irq chip when we
request the irqs and the driver should not be meddling with the
irq?_en registers itself.

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