drivers: adc: nrfx_saadc: Add support for AIN8-AIN13 on nrf54h20

Extend support in dt bindings and in the driver to allow use of
AIN8 to AIN13 analog inputs.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>
4 files changed