regulator: dt-bindings: rtq2208: Add specified fixed LDO VOUT property

As the fixed voltage for the LDO is outside the range of the adjustable voltage mode,
the constraints for this scenario are not suitable to represent both modes.
Therefore, A property is added to specify the fixed LDO VOUT.

Examples of fixed LDO VOUT and adjustable LDO VOUT is also added to this version.

Signed-off-by: Alina Yu <alina_yu@richtek.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://msgid.link/r/c6cb218f6338291525a29ed89a88a42c175127ad.1716870419.git.alina_yu@richtek.com


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