dt-bindings: nfc: Add Documentation for I3C NFC devicetree node

Qualcomm Technologies, Inc SNxxx NFC NCI device

Near Field Communication (NFC) device is based on NFC Controller Interface (NCI).

Refer to I3C bindings file for more information.

Required properties:

- compatible: "qcom,sn-nci-i3c"

- reg: NFC I3C device's PID.

- qcom,sn-ven: specific gpio for hardware reset.

- qcom,sn-firm: gpio for firmware download

- qcom,sn-clkreq: gpio for clock.

Optional properties:

- pinctrl-names, pinctrl-0, pincntrl-1: references to our pincntrl settings.

- clocks, clock-names: must contain the SNxxx's core clock.

- qcom,clk-src: NFC clock for antenna.

- assigned-address: If specific I3C dynamic address is required it can be specified here.

Example:

	sn@0,23600000000 {

		compatible = "qcom,sn-nci-i3c";

		reg = <0 0x236 0x00000000>;

		assigned-address = <0xa>;

		qcom,sn-ven = <&tlmm 62 0x01>;

		qcom,sn-firm = <&tlmm 86 0x00>;

		qcom,sn-clkreq = <&tlmm 63 0x00>;

		qcom,clk-src = "BBCLK2";

		pinctrl-names = "default", "sleep";

		pinctrl-0 = <&nfc_fwdl_active &nfc_clk_req_active>;

		pinctrl-1 = <&nfc_fwdl_suspend &nfc_clk_req_suspend>;

		clocks = <&clock_rpm clk_bb_clk2_pin>;

		clock-names = "ref_clk";

		status = "ok";

	};