Qualcomm Technologies, Inc. RPM SMD cooling device

The RPM shared memory(SMD) cooling device, will be used to set
different thermal band level to RPM hardware. When threshold violation
occurs, RPM SMD cooling device sends pre-configured thermal band level
to RPM hardware via SMD.

Required Parameters:
- compatible:
	Usage: required
	Value type: <string>
	Definition: should be "qcom,rpm-smd-cooling-device"

- #cooling-cells:
	Usage: required
	Value type: <integer>
	Definition: Must be 2. This is required by of-thermal and refer the doc
		<devicetree/bindings/thermal/thermal.txt> for more details.

Example:

&rpm_bus {
	rpm_smd_cdev: rpm-smd-cdev {
		compatible = "qcom,rpm-smd-cooling-device";
		#cooling-cells = <2>;
	};
};