* Superpix SP250A MIPI CSI-2 sensor

Required Properties:
- compatible: should be "superpix,sp250a".
- clocks: reference to the 24M xvclk input clock.
- clock-names: should be "xvclk".
- power-domains: should be "power RK3568_PD_VI" for RK356x.
- dovdd-supply: Digital I/O voltage supply, 1.8/2.8 volts
- avdd-supply: Analog voltage supply, 2.8 volts
- reset-gpios: High active reset gpio
- pwdn-gpios: High active power-down gpio

The device node must contain one 'port' child node for its digital output
video port, and this port must have a single endpoint in accordance with
 the video interface bindings defined in
Documentation/devicetree/bindings/media/video-interfaces.txt.

Endpoint node required properties for CSI-2 connection are:
- remote-endpoint: a phandle to the bus receiver's endpoint node.
- data-lanes: should be set to <1> (one CSI-2 lane supported).

Example:

&i2c2 {
	status = "okay";

	sp250a: sp250a@3c {
		compatible = "superpix,sp250a";
		status = "okay";
		reg = <0x3c>;
		clocks = <&cru CLK_CIF_OUT>;
		clock-names = "xvclk";
		power-domains = <&power RK3568_PD_VI>;
		avdd-supply = <&vcc2v8_dvp>;
		dovdd-supply = <&vcc1v8_dvp>;
		reset-gpios = <&gpio4 RK_PB0 GPIO_ACTIVE_HIGH>;
		pwdn-gpios = <&gpio4 RK_PB3 GPIO_ACTIVE_HIGH>;
		rockchip,camera-module-index = <1>;
		rockchip,camera-module-facing = "front";
		rockchip,camera-module-name = "LM50A60-S107-YK-XJL-V2";
		rockchip,camera-module-lens-name = "default";
		port {
			sp250a_out: endpoint {
				remote-endpoint = <&mipi_in_ucam2>;
				data-lanes = <1>;
			};
		};
	};
};