arm64: dts: rockchip: theoretically enable Wi-Fi on ROCK 4D

The production version of the ROCK 4D appears to sport a AICSEMI
AIC8800D80 USB Wi-Fi + BT chipset. This chip does not yet have a
mainline driver.

Add the necessary rfkill node and wifi regulator node to at least make
it show up in lsusb output. The regulator is set as always-on, as like 2
hours deep into debugging why onboard_usb_dev.c wouldn't try enabling
the regulator the device needs to actually show up and thus bind to
onboard_usb_dev.c, I decided that it's not worth the effort.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20250630-rock4d-reg-usb-wifi-v1-3-1057f412d98c@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: Nicolas Frattaroli

arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts

@@ -37,6 +37,14 @@
 		};
 	};
 
+	rfkill {
+		compatible = "rfkill-gpio";
+		pinctrl-names = "default";
+		pinctrl-0 = <&wifi_en_h>;
+		radio-type = "wlan";
+		shutdown-gpios = <&gpio2 RK_PD1 GPIO_ACTIVE_HIGH>;
+	};
+
 	leds: leds {
 		compatible = "gpio-leds";
 		pinctrl-names = "default";
@@ -159,6 +167,19 @@
 		vin-supply = <&vcc_5v0_sys>;
 	};
 
+	vcc_3v3_wifi: regulator-vcc-3v3-wifi {
+		compatible = "regulator-fixed";
+		enable-active-high;
+		gpios = <&gpio2 RK_PC7 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&usb_wifi_pwr>;
+		regulator-always-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-name = "vcc_3v3_wifi";
+		vin-supply = <&vcc_3v3_s3>;
+	};
+
 	vcc_5v0_device: regulator-vcc-5v0-device {
 		compatible = "regulator-fixed";
 		regulator-always-on;
@@ -720,6 +741,15 @@
 
 		};
 	};
+
+	wifi {
+		usb_wifi_pwr: usb-wifi-pwr {
+			rockchip,pins = <2 RK_PC7 RK_FUNC_GPIO &pcfg_pull_down>;
+		};
+		wifi_en_h: wifi-en-h {
+			rockchip,pins = <2 RK_PD1 RK_FUNC_GPIO &pcfg_pull_down>;
+		};
+	};
 };
 
 &sdmmc {