dt-bindings: i2c: Convert UniPhier FI2C controller to json-schema

Convert the UniPhier FIFO-builtin I2C (a.k.a. FIFO) controller binding
to DT schema format.

There are two types of I2C controllers used on the UniPhier platform.
This is the new one with FIFO support, which is used on the Pro4 SoC
or newer.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt

-UniPhier I2C controller (FIFO-builtin)
-
-Required properties:
-- compatible: should be "socionext,uniphier-fi2c".
-- #address-cells: should be 1.
-- #size-cells: should be 0.
-- reg: offset and length of the register set for the device.
-- interrupts: a single interrupt specifier.
-- clocks: phandle to the input clock.
-
-Optional properties:
-- clock-frequency: desired I2C bus frequency in Hz.  The maximum supported
-  value is 400000.  Defaults to 100000 if not specified.
-
-Examples:
-
-	i2c0: i2c@58780000 {
-		compatible = "socionext,uniphier-fi2c";
-		reg = <0x58780000 0x80>;
-		#address-cells = <1>;
-		#size-cells = <0>;
-		interrupts = <0 41 4>;
-		clocks = <&i2c_clk>;
-		clock-frequency = <100000>;
-	};

Documentation/devicetree/bindings/i2c/socionext,uniphier-fi2c.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/socionext,uniphier-fi2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UniPhier I2C controller (FIFO-builtin)
+
+maintainers:
+  - Masahiro Yamada <yamada.masahiro@socionext.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    const: socionext,uniphier-fi2c
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-frequency:
+    minimum: 100000
+    maximum: 400000
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+  - interrupts
+  - clocks
+
+examples:
+  - |
+    i2c0: i2c@58780000 {
+        compatible = "socionext,uniphier-fi2c";
+        reg = <0x58780000 0x80>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        interrupts = <0 41 4>;
+        clocks = <&i2c_clk>;
+        clock-frequency = <100000>;
+    };