rockchip: rk356x-generic: Add support for SPI flash

Add support for booting from SPI flash using the generic RK3566/RK3568
target.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3568-generic.dts b/arch/arm/dts/rk3568-generic.dts
index 3b9bf80..87c3aff 100644
--- a/arch/arm/dts/rk3568-generic.dts
+++ b/arch/arm/dts/rk3568-generic.dts
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
 /*
- * Minimal generic DT for RK3566/RK3568 with eMMC and SD-card enabled
+ * Minimal generic DT for RK3566/RK3568 with eMMC, SD-card and SPI flash enabled
  */
 
 /dts-v1/;
@@ -43,6 +43,18 @@
 	status = "okay";
 };
 
+&sfc {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <24000000>;
+	};
+};
+
 &uart2 {
 	status = "okay";
 };