spi: dt-bindings: Add bindings for RZ/V2M CSI

Add dt-bindings for the CSI IP found inside the RZ/V2M SoC.
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/Message-Id: <20230622113341.657842-2-fabrizio.castro.jz@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/renesas,rzv2m-csi.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/renesas,rzv2m-csi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/V2M Clocked Serial Interface (CSI)
+
+maintainers:
+  - Fabrizio Castro <fabrizio.castro.jz@renesas.com>
+  - Geert Uytterhoeven <geert+renesas@glider.be>
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+properties:
+  compatible:
+    const: renesas,rzv2m-csi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: The clock used to generate the output clock (CSICLK)
+      - description: Internal clock to access the registers (PCLK)
+
+  clock-names:
+    items:
+      - const: csiclk
+      - const: pclk
+
+  resets:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - resets
+  - power-domains
+  - '#address-cells'
+  - '#size-cells'
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/r9a09g011-cpg.h>
+    csi4: spi@a4020200 {
+        compatible = "renesas,rzv2m-csi";
+        reg = <0xa4020200 0x80>;
+        interrupts = <GIC_SPI 230 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&cpg CPG_MOD R9A09G011_CSI4_CLK>,
+                 <&cpg CPG_MOD R9A09G011_CPERI_GRPH_PCLK>;
+        clock-names = "csiclk", "pclk";
+        resets = <&cpg R9A09G011_CSI_GPH_PRESETN>;
+        power-domains = <&cpg>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+    };