power: supply: axp288-charger: Add depends on IOSF_MBIO to Kconfig

Add "depends on IOSF_MBI" to CONFIG_AXP288_CHARGER as the changes from
commit ed229454 ("power: supply: axp288-charger: Optimize register
reading method") use symbols which are only defined when IOSF_MBI support
is enabled.

Depending on this is ok since IOSF_MBI support should always be enabled
on devices which use the AXP288 PMIC.

Fixes: ed229454 ("power: supply: axp288-charger: Optimize register reading method")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>