arm64: dts: rockchip: Add saradc node to rock5b

Add ADC support for ROCK 5B.
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Link: https://lore.kernel.org/r/20230610134841.172313-1-shreeya.patel@collabora.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts

@@ -207,6 +207,11 @@ &pwm1 {
 	status = "okay";
 };
 
+&saradc {
+	vref-supply = <&avcc_1v8_s0>;
+	status = "okay";
+};
+
 &sdhci {
 	bus-width = <8>;
 	no-sdio;