dt-bindings: power: Add rpm power domain bindings for SDX65

Add RPM power domain bindings for the SDX65 SoC.

Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1647410837-22537-4-git-send-email-quic_rohiagar@quicinc.com