regulator: da9063: add voltage monitoring registers

Add the definitions for the registers responsible for voltage
monitoring. Add a voltage monitor enable bitfield per regulator.

Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Adam Ward <DLG-Adam.Ward.opensource@dm.renesas.com>
Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com>
Link: https://lore.kernel.org/r/20230403-da9063-disable-unused-v3-1-cc4dc698864c@skidata.com


Signed-off-by: Mark Brown <broonie@kernel.org>