dt-bindings: soc: sprd: sc9863a-glbregs: Document SC9863A syscon

Document sprd,sc9863a-glbregs compatible already used in DTS and other
bindings example.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240626-dt-bindings-mfd-syscon-split-v3-2-3409903bb99b@linaro.orgSigned-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/soc/sprd/sprd,sc9863a-glbregs.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/sprd/sprd,sc9863a-glbregs.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SC9863A Syscon
+
+maintainers:
+  - Orson Zhai <orsonzhai@gmail.com>
+  - Baolin Wang <baolin.wang7@gmail.com>
+  - Chunyan Zhang <zhang.lyra@gmail.com>
+
+properties:
+  compatible:
+    items:
+      - const: sprd,sc9863a-glbregs
+      - const: syscon
+      - const: simple-mfd
+
+  reg:
+    maxItems: 1
+
+  ranges: true
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+patternProperties:
+  "@[0-9a-f]+$":
+    $ref: /schemas/clock/sprd,sc9863a-clk.yaml
+    description: Clock controllers
+
+additionalProperties: false
+
+examples:
+  - |
+    syscon@20e00000 {
+      compatible = "sprd,sc9863a-glbregs", "syscon", "simple-mfd";
+      reg = <0x20e00000 0x4000>;
+      ranges = <0 0x20e00000 0x4000>;
+      #address-cells = <1>;
+      #size-cells = <1>;
+
+      apahb_gate: apahb-gate@0 {
+        compatible = "sprd,sc9863a-apahb-gate";
+        reg = <0x0 0x1020>;
+        #clock-cells = <1>;
+      };
+    };
+
+...