dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR

Add qcom-opp bindings with properties needed for Core Power Reduction
(CPR).

CPR is included in a great variety of Qualcomm SoCs, e.g. msm8916 and
msm8996. CPR was first introduced in msm8974.

Co-developed-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>