dt-bindings: power: qcom,rpmhpd: Add Generic RPMh PD indexes

dt-bindings: power: qcom,rpmhpd: Add Generic RPMh PD indexes

Add Generic RPMh Power Domain indexes that can be used
for all the Qualcomm SoC henceforth.
The power domain indexes of these bindings are based on compatibility
with current targets like SM8[2345]50 targets.

Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Suggested-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/1689744162-9421-2-git-send-email-quic_rohiagar@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>