dt-bindings: rtc: qcom-pm8xxx-rtc: Add qcom pm8xxx rtc bindings

Add binding doc for qcom pm8xxx rtc device.
Signed-off-by: satya priya <skakit@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1617976766-7852-5-git-send-email-skakit@codeaurora.org

Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/qcom-pm8xxx-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm PM8xxx PMIC RTC device
+
+maintainers:
+  - Satya Priya <skakit@codeaurora.org>
+
+properties:
+  compatible:
+    enum:
+      - qcom,pm8058-rtc
+      - qcom,pm8921-rtc
+      - qcom,pm8941-rtc
+      - qcom,pm8018-rtc
+      - qcom,pmk8350-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  allow-set-time:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Indicates that the setting of RTC time is allowed by the host CPU.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/spmi/spmi.h>
+    spmi_bus: spmi@c440000 {
+      reg = <0x0c440000 0x1100>;
+      #address-cells = <2>;
+      #size-cells = <0>;
+      pmicintc: pmic@0 {
+        reg = <0x0 SPMI_USID>;
+        compatible = "qcom,pm8921";
+        interrupts = <104 8>;
+        #interrupt-cells = <2>;
+        interrupt-controller;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pm8921_rtc: rtc@11d {
+          compatible = "qcom,pm8921-rtc";
+          reg = <0x11d>;
+          interrupts = <0x27 0>;
+        };
+      };
+    };
+...