dt-bindings: soc: samsung: exynos-sysreg: split from syscon

Split Samsung Exynos SoC SYSREG bindings to own file to narrow the
bindings and do not allow other parts of syscon.yaml.  This allows
further customization of Samsung SoC bindings.
Acked-by: Lee Jones <lee@kernel.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Sriranjani P <sriranjani.p@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221127123259.20339-2-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Documentation/devicetree/bindings/mfd/syscon.yaml

@@ -64,12 +64,6 @@ properties:
               - rockchip,rk3568-qos
               - rockchip,rk3588-qos
               - rockchip,rv1126-qos
-              - samsung,exynos3-sysreg
-              - samsung,exynos4-sysreg
-              - samsung,exynos5-sysreg
-              - samsung,exynos5433-sysreg
-              - samsung,exynos850-sysreg
-              - samsung,exynosautov9-sysreg
 
           - const: syscon
 

Documentation/devicetree/bindings/soc/samsung/samsung,exynos-sysreg.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/samsung/samsung,exynos-sysreg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung Exynos SoC series System Registers (SYSREG)
+
+maintainers:
+  - Krzysztof Kozlowski <krzk@kernel.org>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - samsung,exynos3-sysreg
+              - samsung,exynos4-sysreg
+              - samsung,exynos5-sysreg
+              - samsung,exynos5433-sysreg
+              - samsung,exynos850-sysreg
+              - samsung,exynosautov9-sysreg
+          - const: syscon
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    system-controller@10010000 {
+        compatible = "samsung,exynos4-sysreg", "syscon";
+        reg = <0x10010000 0x400>;
+    };