CONFIG_ZMK_BATTERY_NRF_VDDH and CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER are now automatically enabled if a DT node with the matching "compatible" property is present and enabled, so they no longer need to be manually set for each board.
See: https://docs.zephyrproject.org/latest/releases/release-notes-2.6.html#api-changes
Added a driver which uses the nRF52's ADC channel on the VDDH pin to read the battery voltage when using high voltage mode.