dt-bindings: net: wireless: Convert ESP ESP8089 binding to a schema

The ESP8089 Wireless Chip is supported by Linux (through an out-of-tree
driver) thanks to its device tree binding.

Now that we have the DT validation in place, let's convert the device
tree bindings for that driver over to a YAML schema.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: de Goede <hdegoede@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210924072756.869731-4-maxime@cerno.tech

Documentation/devicetree/bindings/net/wireless/esp,esp8089.txt

-Espressif ESP8089 wireless SDIO devices
-
-This node provides properties for controlling the ESP8089 wireless device.
-The node is expected to be specified as a child node to the SDIO controller
-that connects the device to the system.
-
-Required properties:
-
- - compatible : Should be "esp,esp8089".
-
-Optional properties:
- - esp,crystal-26M-en: Integer value for the crystal_26M_en firmware parameter
-
-Example:
-
-&mmc1 {
-	#address-cells = <1>;
-	#size-cells = <0>;
-
-	vmmc-supply = <&reg_dldo1>;
-	mmc-pwrseq = <&wifi_pwrseq>;
-	bus-width = <4>;
-	non-removable;
-
-	esp8089: sdio_wifi@1 {
-		compatible = "esp,esp8089";
-		reg = <1>;
-		esp,crystal-26M-en = <2>;
-	};
-};

Documentation/devicetree/bindings/net/wireless/esp,esp8089.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/wireless/esp,esp8089.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Espressif ESP8089 Device Tree Bindings
+
+maintainers:
+  - Hans de Goede <hdegoede@redhat.com>
+
+properties:
+  compatible:
+    const: esp,esp8089
+
+  reg:
+    maxItems: 1
+
+  esp,crystal-26M-en:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: >
+      Value for the crystal_26M_en firmware parameter
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+      mmc {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          wifi@1 {
+              compatible = "esp,esp8089";
+              reg = <1>;
+              esp,crystal-26M-en = <2>;
+          };
+      };
+
+...