dt-bindings: i3c: Convert cdns,i3c-master to DT schema

Convert the Cadence I3C master to DT schema format. This fixes a warning
as it is used in the i3c.yaml example.

The "nintendo,nunchuk" is not documented by a schema, so change the
example child device to something which is documented.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220422192224.2594098-1-robh@kernel.org

Documentation/devicetree/bindings/i3c/cdns,i3c-master.txt

-Bindings for cadence I3C master block
-=====================================
-
-Required properties:
---------------------
-- compatible: shall be "cdns,i3c-master"
-- clocks: shall reference the pclk and sysclk
-- clock-names: shall contain "pclk" and "sysclk"
-- interrupts: the interrupt line connected to this I3C master
-- reg: I3C master registers
-
-Mandatory properties defined by the generic binding (see
-Documentation/devicetree/bindings/i3c/i3c.yaml for more details):
-
-- #address-cells: shall be set to 1
-- #size-cells: shall be set to 0
-
-Optional properties defined by the generic binding (see
-Documentation/devicetree/bindings/i3c/i3c.yaml for more details):
-
-- i2c-scl-hz
-- i3c-scl-hz
-
-I3C device connected on the bus follow the generic description (see
-Documentation/devicetree/bindings/i3c/i3c.yaml for more details).
-
-Example:
-
-	i3c-master@0d040000 {
-		compatible = "cdns,i3c-master";
-		clocks = <&coreclock>, <&i3csysclock>;
-		clock-names = "pclk", "sysclk";
-		interrupts = <3 0>;
-		reg = <0x0d040000 0x1000>;
-		#address-cells = <1>;
-		#size-cells = <0>;
-		i2c-scl-hz = <100000>;
-
-		nunchuk: nunchuk@52 {
-			compatible = "nintendo,nunchuk";
-			reg = <0x52 0x0 0x10>;
-		};
-	};

Documentation/devicetree/bindings/i3c/cdns,i3c-master.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i3c/cdns,i3c-master.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cadence I3C master block
+
+maintainers:
+  - Boris Brezillon <bbrezillon@kernel.org>
+
+allOf:
+  - $ref: i3c.yaml#
+
+properties:
+  compatible:
+    const: cdns,i3c-master
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: pclk
+      - const: sysclk
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i3c-master@d040000 {
+        compatible = "cdns,i3c-master";
+        clocks = <&coreclock>, <&i3csysclock>;
+        clock-names = "pclk", "sysclk";
+        interrupts = <3 0>;
+        reg = <0x0d040000 0x1000>;
+        #address-cells = <3>;
+        #size-cells = <0>;
+        i2c-scl-hz = <100000>;
+
+        eeprom@57{
+            compatible = "atmel,24c01";
+            reg = <0x57 0x0 0x10>;
+            pagesize = <0x8>;
+        };
+    };
+...