dt-bindings: clock: renesas: div6: Convert to json-schema

Convert the Renesas CPG DIV6 Clock Device Tree binding documentation to
json-schema.

Drop R-Car Gen2 compatible values, which were obsoleted by the unified
"Renesas Clock Pulse Generator / Module Standby and Software Reset" DT
bindings.
Update the example to match reality.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Niklas Söderlund <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: geertu

Documentation/devicetree/bindings/clock/renesas,cpg-div6-clock.yaml

@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/renesas,cpg-div6-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas CPG DIV6 Clock
+
+maintainers:
+  - Geert Uytterhoeven <[email protected]>
+
+description:
+  The CPG DIV6 clocks are variable factor clocks provided by the Clock Pulse
+  Generator (CPG). Their clock input is divided by a configurable factor from 1
+  to 64.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - renesas,r8a73a4-div6-clock # R-Mobile APE6
+          - renesas,r8a7740-div6-clock # R-Mobile A1
+          - renesas,sh73a0-div6-clock  # SH-Mobile AG5
+      - const: renesas,cpg-div6-clock
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    oneOf:
+      - maxItems: 1
+      - maxItems: 4
+      - maxItems: 8
+    description:
+      For clocks with multiple parents, invalid settings must be specified as
+      "<0>".
+
+  '#clock-cells':
+    const: 0
+
+  clock-output-names: true
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r8a73a4-clock.h>
+    sdhi2_clk: sdhi2_clk@e615007c {
+            compatible = "renesas,r8a73a4-div6-clock", "renesas,cpg-div6-clock";
+            reg = <0xe615007c 4>;
+            clocks = <&pll1_div2_clk>, <&cpg_clocks R8A73A4_CLK_PLL2S>, <0>,
+                     <&extal2_clk>;
+            #clock-cells = <0>;
+    };