dt-bindings: soc: google: Add gs101-pmu-intr-gen binding documentation

Add bindings documentation for the Power Management Unit (PMU) interrupt
generator.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20250506-contrib-pg-cpu-hotplug-suspend2ram-fixes-v1-v4-1-9f64a2657316@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml

@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/google/google,gs101-pmu-intr-gen.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Power Management Unit (PMU) Interrupt Generation
+
+description: |
+  PMU interrupt generator for handshaking between PMU through interrupts.
+
+maintainers:
+  - Peter Griffin <peter.griffin@linaro.org>
+
+properties:
+  compatible:
+    items:
+      - const: google,gs101-pmu-intr-gen
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    pmu_intr_gen: syscon@17470000 {
+      compatible = "google,gs101-pmu-intr-gen", "syscon";
+      reg = <0x17470000 0x10000>;
+    };