dt-bindings: convert the binding document for mediatek PERICFG to yaml

Convert the DT binding .txt file for MediaTek's peripheral configuration
controller to YAML. There's one special case where the compatible has
three positions. Otherwise, it's a pretty normal syscon.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/arm/mediatek/mediatek,pericfg.yaml

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/arm/mediatek/mediatek,pericfg.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: MediaTek Peripheral Configuration Controller
+
+maintainers:
+  - Bartosz Golaszewski <bgolaszewski@baylibre.com>
+
+description:
+  The Mediatek pericfg controller provides various clocks and reset outputs
+  to the system.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+        - enum:
+          - mediatek,mt2701-pericfg
+          - mediatek,mt2712-pericfg
+          - mediatek,mt7622-pericfg
+          - mediatek,mt7629-pericfg
+          - mediatek,mt8135-pericfg
+          - mediatek,mt8173-pericfg
+          - mediatek,mt8183-pericfg
+        - const: syscon
+      - items:
+        # Special case for mt7623 for backward compatibility
+        - const: mediatek,mt7623-pericfg
+        - const: mediatek,mt2701-pericfg
+        - const: syscon
+
+  reg:
+    maxItems: 1
+
+  '#clock-cells':
+    const: 1
+
+  '#reset-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    pericfg@10003000 {
+        compatible = "mediatek,mt8173-pericfg", "syscon";
+        reg = <0x10003000 0x1000>;
+        #clock-cells = <1>;
+        #reset-cells = <1>;
+    };
+
+  - |
+    pericfg@10003000 {
+        compatible =  "mediatek,mt7623-pericfg", "mediatek,mt2701-pericfg", "syscon";
+        reg = <0x10003000 0x1000>;
+        #clock-cells = <1>;
+        #reset-cells = <1>;
+    };