dt-bindings: interrupt-controller: Add fsl,icoll.yaml

Add fsl,icoll.yaml for i.MX23 and i.MX28.

Also add a generic fallback compatible string "fsl,icoll" for legacy
devices, which have existed for over 15 years.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250724164624.1271661-1-Frank.Li@nxp.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Documentation/devicetree/bindings/interrupt-controller/fsl,icoll.yaml

@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/fsl,icoll.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale MXS icoll Interrupt controller
+
+maintainers:
+  - Frank Li <Frank.Li@nxp.com>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - fsl,imx23-icoll
+              - fsl,imx28-icoll
+          - const: fsl,icoll
+
+  reg:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - '#interrupt-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    interrupt-controller@80000000 {
+        compatible = "fsl,imx28-icoll", "fsl,icoll";
+        reg = <0x80000000 0x2000>;
+        interrupt-controller;
+        #interrupt-cells = <1>;
+    };
+