dt-bindings: power: qcom-rpmpd: add generic bindings for RPM power domains

dt-bindings: power: qcom-rpmpd: add generic bindings for RPM power domains

Some of the Qualcomm RPM PD controllers use a common set of indices for
power domains. Add generic indices for Qualcomm RPM power domain
controllers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20250718-rework-rpmhpd-rpmpd-v1-3-eedca108e540@oss.qualcomm.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>