Add device tree binding documentation for the Qualcomm GLINK RPM, used for communication with the Resource Power Management subsystem in various Qualcomm SoCs. Acked-by: Andy Gross <andy.gross@linaro.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>