of: dynamic: Introduce of_changeset_add_prop_bool()

APIs to add some properties in a changeset exist but nothing to add a DT
boolean property (i.e. a property without any values).

Fill this lack with of_changeset_add_prop_bool().

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/20240527161450.326615-16-herve.codina@bootlin.com


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>