drivers: nordic: support pin retention for AIN

Devices which use AIN (COMP, LPCOMP, SAADC) don't use pinctrl to
configure their pins, thus pinctrl can't manage pin retention like
is done for other devices. Thus for now, add manually disabling
pin retention to the drivers.

In the future, we should probably use pinctrl for these inputs
as well, at which point this commit can be reverted.

Signed-off-by: Bjarki Arge Andreasen <bjarki.andreasen@nordicsemi.no>
3 files changed