dt-bindings: nfc: nxp,nci: convert to dtschema

Convert the NXP NCI NFC controller to DT schema format.

Drop the "clock-frequency" property during conversion because it is a
property of I2C bus controller, not I2C slave device.  It was also never
used by the driver.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211011073934.34340-2-krzysztof.kozlowski@canonical.com
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/nfc/nxp,nci.yaml

@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/nfc/nxp,nci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP Semiconductors NCI NFC controller
+
+maintainers:
+  - Charles Gorand <charles.gorand@effinnov.com>
+  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+
+properties:
+  compatible:
+    const: nxp,nxp-nci-i2c
+
+  enable-gpios:
+    description: Output GPIO pin used for enabling/disabling the controller
+
+  firmware-gpios:
+    description: Output GPIO pin used to enter firmware download mode
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - enable-gpios
+  - interrupts
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nfc@29 {
+            compatible = "nxp,nxp-nci-i2c";
+
+            reg = <0x29>;
+
+            interrupt-parent = <&gpio1>;
+            interrupts = <29 IRQ_TYPE_LEVEL_HIGH>;
+
+            enable-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;
+            firmware-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>;
+        };
+    };