arm64: dts: rockchip: Enable SPI flash on PinePhone Pro

The PinePhone Pro as SPI flash on board so enable the SPI
interface and the flash.
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20240623204616.1344806-1-pbrobinson@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts

@@ -565,6 +565,16 @@ &sdhci {
 	status = "okay";
 };
 
+&spi1 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <10000000>;
+	};
+};
+
 &tsadc {
 	rockchip,hw-tshut-mode = <1>;
 	rockchip,hw-tshut-polarity = <1>;