dt-bindings: thermal: Add dt binding for QCOM LMh

Add dt binding documentation to describe Qualcomm
Limits Management Hardware node.
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210809191605.3742979-8-thara.gopinath@linaro.org

Documentation/devicetree/bindings/thermal/qcom-lmh.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2021 Linaro Ltd.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/qcom-lmh.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Limits Management Hardware(LMh)
+
+maintainers:
+  - Thara Gopinath <thara.gopinath@linaro.org>
+
+description:
+  Limits Management Hardware(LMh) is a hardware infrastructure on some
+  Qualcomm SoCs that can enforce temperature and current limits as
+  programmed by software for certain IPs like CPU.
+
+properties:
+  compatible:
+    enum:
+      - qcom,sdm845-lmh
+
+  reg:
+    items:
+      - description: core registers
+
+  interrupts:
+    maxItems: 1
+
+  '#interrupt-cells':
+    const: 1
+
+  interrupt-controller: true
+
+  cpus:
+    description:
+      phandle of the first cpu in the LMh cluster
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  qcom,lmh-temp-arm-millicelsius:
+    description:
+      An integer expressing temperature threshold at which the LMh thermal
+      FSM is engaged.
+
+  qcom,lmh-temp-low-millicelsius:
+    description:
+      An integer expressing temperature threshold at which the state machine
+      will attempt to remove frequency throttling.
+
+  qcom,lmh-temp-high-millicelsius:
+    description:
+      An integer expressing temperature threshold at which the state machine
+      will attempt to throttle the frequency.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - '#interrupt-cells'
+  - interrupt-controller
+  - cpus
+  - qcom,lmh-temp-arm-millicelsius
+  - qcom,lmh-temp-low-millicelsius
+  - qcom,lmh-temp-high-millicelsius
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    lmh@17d70800 {
+      compatible = "qcom,sdm845-lmh";
+      reg = <0x17d70800 0x400>;
+      interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
+      cpus = <&CPU4>;
+      qcom,lmh-temp-arm-millicelsius = <65000>;
+      qcom,lmh-temp-low-millicelsius = <94500>;
+      qcom,lmh-temp-high-millicelsius = <95000>;
+      interrupt-controller;
+      #interrupt-cells = <1>;
+    };