dt-bindings: Introduce SoC sleep stats bindings

Add device binding documentation for Qualcomm Technologies, Inc. (QTI)
SoC sleep stats driver. The driver is used for displaying SoC sleep
statistic maintained by Always On Processor or Resource Power Manager.

Change-Id: I002c67010c91a4d9f33eb73a2522f4e3b295ba99

bindings/soc/qcom/soc-sleep-stats.yaml

@@ -0,0 +1,45 @@
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/soc-sleep-stats.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Technologies, Inc. (QTI) SoC sleep stats bindings
+
+maintainers:
+  - Maulik Shah <mkshah@codeaurora.org>
+  - Lina Iyer <ilina@codeaurora.org>
+
+description:
+  Always On Processor/Resource Power Manager maintains statistics of the SoC
+  sleep modes involving powering down of the rails and oscillator clock.
+
+  Statistics includes SoC sleep mode type, number of times low power mode were
+  entered, time of last entry, time of last exit and accumulated sleep duration.
+
+properties:
+  compatible:
+    enum:
+      - qcom,rpmh-sleep-stats
+      - qcom,rpm-sleep-stats
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  # Example of rpmh sleep stats
+  - |
+    rpmh-sleep-stats@c3f0000 {
+      compatible = "qcom,rpmh-sleep-stats";
+      reg = <0 0xc3f0000 0 0x400>;
+    };
+  # Example of rpm sleep stats
+  - |
+    rpm-sleep-stats@4690000 {
+      compatible = "qcom,rpm-sleep-stats";
+      reg = <0 0x04690000 0 0x400>;
+    };
+...