dt-bindings: soc: ti: am654-serdes-ctrl: Move to dedicated schema

ti,am654-serdes-ctrl is not a simple syscon device - it has children -
thus it should be fully documented in its own binding.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240626-dt-bindings-mfd-syscon-split-v3-5-3409903bb99b@linaro.orgSigned-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/mfd/syscon.yaml

@@ -88,7 +88,6 @@ properties:
               - ti,am62-usb-phy-ctrl
               - ti,am62p-cpsw-mac-efuse
               - ti,am654-dss-oldi-io-ctrl
-              - ti,am654-serdes-ctrl
               - ti,j784s4-pcie-ctrl
 
           - const: syscon

Documentation/devicetree/bindings/soc/ti/ti,am654-serdes-ctrl.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/ti/ti,am654-serdes-ctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments AM654 Serdes Control Syscon
+
+maintainers:
+  - Nishanth Menon <nm@ti.com>
+
+properties:
+  compatible:
+    items:
+      - const: ti,am654-serdes-ctrl
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  mux-controller:
+    $ref: /schemas/mux/reg-mux.yaml#
+
+required:
+  - compatible
+  - reg
+  - mux-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    clock@4080 {
+        compatible = "ti,am654-serdes-ctrl", "syscon";
+        reg = <0x4080 0x4>;
+
+        mux-controller {
+            compatible = "mmio-mux";
+            #mux-control-cells = <1>;
+            mux-reg-masks = <0x0 0x3>; /* lane select */
+        };
+    };