spi: Convert bcm63xx-hsspi bindings to json-schema

This is the preparation for updates on the bcm63xx hsspi driver. Convert
the text based bindings to json-schema per new dts requirement.
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Link: https://lore.kernel.org/r/20230207065826.285013-2-william.zhang@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml

+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/brcm,bcm63xx-hsspi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM6328 High Speed SPI controller
+
+maintainers:
+  - Jonas Gorski <jonas.gorski@gmail.com>
+
+properties:
+  compatible:
+    const: brcm,bcm6328-hsspi
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: SPI master reference clock
+      - description: SPI master pll clock
+
+  clock-names:
+    items:
+      - const: hsspi
+      - const: pll
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    spi@10001000 {
+        compatible = "brcm,bcm6328-hsspi";
+        reg = <0x10001000 0x600>;
+        interrupts = <29>;
+        clocks = <&clkctl 9>, <&hsspi_pll>;
+        clock-names = "hsspi", "pll";
+        num-cs = <2>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+    };

Documentation/devicetree/bindings/spi/spi-bcm63xx-hsspi.txt

-Binding for Broadcom BCM6328 High Speed SPI controller
-
-Required properties:
-- compatible: must contain of "brcm,bcm6328-hsspi".
-- reg: Base address and size of the controllers memory area.
-- interrupts: Interrupt for the SPI block.
-- clocks: phandles of the SPI clock and the PLL clock.
-- clock-names: must be "hsspi", "pll".
-- #address-cells: <1>, as required by generic SPI binding.
-- #size-cells: <0>, also as required by generic SPI binding.
-
-Optional properties:
-- num-cs: some controllers have less than 8 cs signals. Defaults to 8
-  if absent.
-
-Child nodes as per the generic SPI binding.
-
-Example:
-
-	spi@10001000 {
-		compatible = "brcm,bcm6328-hsspi";
-		reg = <0x10001000 0x600>;
-
-		interrupts = <29>;
-
-		clocks = <&clkctl 9>, <&hsspi_pll>;
-		clock-names = "hsspi", "pll";
-
-		num-cs = <2>;
-
-		#address-cells = <1>;
-		#size-cells = <0>;
-	};