dt-bindings: power: Add qcom rpm power domain driver bindings

dt-bindings: power: Add qcom rpm power domain driver bindings

Add DT bindings to describe the rpm/rpmh power domains found on Qualcomm
Technologies, Inc. SoCs. These power domains communicate a performance
state to RPM/RPMh, which then translates it into corresponding voltage on a
PMIC rail.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>