dt-bindings: net: bluetooth: Add rtl8723bs-bluetooth

Add binding document for bluetooth part of RTL8723BS/RTL8723CS
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Documentation/devicetree/bindings/net/realtek-bluetooth.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/realtek-bluetooth.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RTL8723BS/RTL8723CS/RTL8822CS Bluetooth Device Tree Bindings
+
+maintainers:
+  - Vasily Khoruzhick <anarsoul@gmail.com>
+  - Alistair Francis <alistair@alistair23.me>
+
+description:
+  RTL8723CS/RTL8723CS/RTL8822CS is WiFi + BT chip. WiFi part is connected over
+  SDIO, while BT is connected over serial. It speaks H5 protocol with few
+  extra commands to upload firmware and change module speed.
+
+properties:
+  compatible:
+    oneOf:
+      - const: "realtek,rtl8723bs-bt"
+      - const: "realtek,rtl8723cs-bt"
+      - const: "realtek,rtl8822cs-bt"
+
+  device-wake-gpios:
+    maxItems: 1
+    description: GPIO specifier, used to wakeup the BT module
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO specifier, used to enable the BT module
+
+  host-wake-gpios:
+    maxItems: 1
+    description: GPIO specifier, used to wakeup the host processor
+
+required:
+  - compatible
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    uart1 {
+        pinctrl-names = "default";
+        pinctrl-0 = <&uart1_pins>, <&uart1_rts_cts_pins>;
+        uart-has-rtscts = <1>;
+
+        bluetooth {
+            compatible = "realtek,rtl8723bs-bt";
+            device-wake-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* PL5 */
+            host-wakeup-gpios = <&r_pio 0 6 GPIO_ACTIVE_HIGH>; /* PL6 */
+        };
+    };