dt-bindings: soc: intel: lgm-syscon: Move to dedicated schema

intel,lgm-syscon is not a simple syscon device - it has children - thus
it should be fully documented in its own binding.

Reviewed-by: Conor Dooley <[e-mail]>
Reviewed-by: Rob Herring (Arm) <[e-mail]>
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

Documentation/devicetree/bindings/mfd/syscon.yaml

···
               - hisilicon,pcie-sas-subctrl
               - hisilicon,peri-subctrl
               - hpe,gxp-sysreg
-              - intel,lgm-syscon
               - loongson,ls1b-syscon
               - loongson,ls1c-syscon
               - marvell,armada-3700-cpu-misc

Documentation/devicetree/bindings/soc/intel/intel,lgm-syscon.yaml

···
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/intel/intel,lgm-syscon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Lightning Mountain(LGM) Syscon
+
+maintainers:
+  - Chuanhua Lei <[e-mail]>
+  - Rahul Tanwar <[e-mail]>
+
+properties:
+  compatible:
+    items:
+      - const: intel,lgm-syscon
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  ranges: true
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+patternProperties:
+  "^emmc-phy@[0-9a-f]+$":
+    $ref: /schemas/phy/intel,lgm-emmc-phy.yaml#
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    chiptop@e0200000 {
+        compatible = "intel,lgm-syscon", "syscon";
+        reg = <0xe0200000 0x100>;
+        ranges = <0x0 0xe0200000 0x100>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        emmc-phy@a8 {
+            compatible = "intel,lgm-emmc-phy";
+            reg = <0x00a8 0x10>;
+            clocks = <&emmc>;
+            #phy-cells = <0>;
+        };
+    };