arm64: dts: rockchip: add RK3576 RNG node

The RK3576 has a hardware random number generator IP built into the SoC.

Add it to the SoC's .dtsi, now that there's a binding and driver for it.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20250430-rk3576-hwrng-v1-3-480c15b5843e@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>