media: dt-bindings: Convert Omnivision OV7251 to DT schema

Convert the OmniVision OV7251 Image Sensor binding to DT schema format.

vddd-supply was listed as required, but the example and actual user
don't have it. Also, the data brief says it has an internal regulator,
so perhaps it is truly optional.

Add missing common "link-frequencies" which is used and required by the
Linux driver.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Link: https://lore.kernel.org/r/20230817202713.2180195-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml

@@ -269,6 +269,7 @@ examples:
                 port {
                     ov7251_ep: endpoint {
                         data-lanes = <0 1>;
+                        link-frequencies = /bits/ 64 <240000000 319200000>;
                         remote-endpoint = <&csiphy3_ep>;
                     };
                 };

Documentation/devicetree/bindings/media/i2c/ovti,ov7251.yaml

@@ -0,0 +1,109 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/ovti,ov7251.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: OmniVision OV7251 Image Sensor
+
+description:
+  The Omnivision OV7251 is a 1/7.5-Inch CMOS active pixel digital image sensor
+  with an active array size of 640H x 480V. It is programmable through a serial
+  I2C interface.
+
+maintainers:
+  - Todor Tomov <todor.too@gmail.com>
+
+properties:
+  compatible:
+    const: ovti,ov7251
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: XCLK Input Clock
+
+  clock-names:
+    const: xclk
+
+  clock-frequency:
+    description: Frequency of the xclk clock in Hz.
+
+  vdda-supply:
+    description: Analog voltage supply, 2.8 volts
+
+  vddd-supply:
+    description: Digital core voltage supply, 1.2 volts
+
+  vdddo-supply:
+    description: Digital I/O voltage supply, 1.8 volts
+
+  enable-gpios:
+    maxItems: 1
+    description:
+      Reference to the GPIO connected to the XSHUTDOWN pin, if any. Polarity
+      is GPIO_ACTIVE_HIGH.
+
+  port:
+    description: Digital Output Port
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    additionalProperties: false
+
+    properties:
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          clock-lanes:
+            maximum: 1
+
+          data-lanes:
+            maxItems: 1
+
+          link-frequencies: true
+
+        required:
+          - data-lanes
+          - link-frequencies
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - vdddo-supply
+  - vdda-supply
+  - port
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        camera@3c {
+            compatible = "ovti,ov7251";
+            reg = <0x3c>;
+            clocks = <&clks 1>;
+            clock-frequency = <24000000>;
+            vdddo-supply = <&ov7251_vdddo_1v8>;
+            vdda-supply = <&ov7251_vdda_2v8>;
+            vddd-supply = <&ov7251_vddd_1v5>;
+            enable-gpios = <&gpio1 19 GPIO_ACTIVE_HIGH>;
+
+            port {
+                ov7251_ep: endpoint {
+                    remote-endpoint = <&csi0_ep>;
+                    clock-lanes = <1>;
+                    data-lanes = <0>;
+                    link-frequencies = /bits/ 64 <240000000 319200000>;
+                };
+            };
+        };
+    };
+...