regulator: dt-bindings: Add system-critical-regulator property

regulator: dt-bindings: Add system-critical-regulator property

Introduce a new Device Tree property 'system-critical-regulator' for
marking a regulator as crucial for system stability or functionality.
This helps in distinguishing regulators that are vital for system
operations and may require special handling in under-voltage scenarios.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231026144824.4065145-2-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>