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

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>