dt-bindings: soc: imx: add binding doc for aips bus

Add binding doc for fsl,aips-bus
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/soc/imx/fsl,aips-bus.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/imx/fsl,aips-bus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: i.MX AHB to IP Bridge
+
+maintainers:
+  - Peng Fan <peng.fan@nxp.com>
+
+description: |
+  This particular peripheral is designed as the bridge between
+  AHB bus and peripherals with the lower bandwidth IP Slave (IPS)
+  buses.
+
+select:
+  properties:
+    compatible:
+      contains:
+        const: fsl,aips-bus
+  required:
+    - compatible
+
+properties:
+  compatible:
+    items:
+      - const: fsl,aips-bus
+      - const: simple-bus
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    bus@30000000 {
+      compatible = "fsl,aips-bus", "simple-bus";
+      reg = <0x30000000 0x400000>;
+      #address-cells = <1>;
+      #size-cells = <1>;
+      ranges;
+    };
+...