regulator: dt-bindings: rtq2208: Add Richtek RTQ2208 SubPMIC

Add bindings for Richtek RTQ2208 IC controlled SubPMIC

Signed-off-by: Alina Yu <alina_yu@richtek.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/1691389687-31211-2-git-send-email-alina_yu@richtek.com


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