dt-bindings: soc: altera: convert socfpga-system.txt to yaml

Convert socfpga-system.txt to altr,socfpga-sys-mgr.yaml and move to
soc directory.

Add platform names in description for clarity. ARM(32-bit) platforms
Cyclone5, Arria5 and Arria10 is using "altr,sys-mgr" compatible,
while ARM64 is using "altr,sys-mgr-s10" compatible.
Removed "cpu1-start-addr" for ARM64 as it is not required.

Signed-off-by: Niravkumar L Rabara <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring (Arm) <[e-mail]>

Documentation/devicetree/bindings/arm/altera/socfpga-system.txt

···
-Altera SOCFPGA System Manager
-
-Required properties:
-- compatible : "altr,sys-mgr"
-- reg : Should contain 1 register ranges(address and length)
-- cpu1-start-addr : CPU1 start address in hex.
-
-Example:
-	 sysmgr@ffd08000 {
-		compatible = "altr,sys-mgr";
-		reg = <0xffd08000 0x1000>;
-		cpu1-start-addr = <0xffd080c4>;
-	};
-
-ARM64 - Stratix10
-Required properties:
-- compatible : "altr,sys-mgr-s10"
-- reg : Should contain 1 register range(address and length)
-        for system manager register.
-
-Example:
-	 sysmgr@ffd12000 {
-		compatible = "altr,sys-mgr-s10";
-		reg = <0xffd12000 0x228>;
-	};

Documentation/devicetree/bindings/soc/altera/altr,sys-mgr.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/altera/altr,sys-mgr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Altera SOCFPGA System Manager
+
+maintainers:
+  - Dinh Nguyen <[e-mail]>
+
+properties:
+  compatible:
+    oneOf:
+      - description: Cyclone5/Arria5/Arria10
+        const: altr,sys-mgr
+      - description: Stratix10 SoC
+        items:
+          - const: altr,sys-mgr-s10
+          - const: altr,sys-mgr
+
+  reg:
+    maxItems: 1
+
+  cpu1-start-addr:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: CPU1 start address in hex
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: altr,sys-mgr-s10
+    then:
+      properties:
+        cpu1-start-addr: false
+
+additionalProperties: false
+
+examples:
+  - |
+    sysmgr@ffd08000 {
+      compatible = "altr,sys-mgr";
+      reg = <0xffd08000 0x1000>;
+      cpu1-start-addr = <0xffd080c4>;
+    };