dt-bindings: soc: qcom,rpmh-rsc: Limit power-domains requirement

dt-bindings: soc: qcom,rpmh-rsc: Limit power-domains requirement

Certain platforms (such as Chrome SDM845 and SC7180 with a TF-A running
as secure firmware) do not have a OSI-mode capable PSCI implementation.

That in turn means the PSCI-associated power domain which represents the
system's power state can't provide enough feedback to the RSC device.

Don't require power-domains on platforms where this may be the case.

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250327-topic-more_dt_bindings_fixes-v2-1-b763d958545f@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>