arm: rockchip: sync ROCK Pi 4A DTS from Linux

To prepare for ROCK Pi 4A SPI flash support, sync the DTS from Linux which
includes an SPI flash node.

Kernel tag: v6.6-rc1
Kernel commits:
 - eddf73029770 ("arm64: dts: rockchip: Enable internal SPI flash for ROCK \
                  Pi 4A/B/C")

Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Reviewed-by: Jonas Karlman <jonas@kwiboo.se>
diff --git a/arch/arm/dts/rk3399-rock-pi-4a.dts b/arch/arm/dts/rk3399-rock-pi-4a.dts
index 931334a..d5df893 100644
--- a/arch/arm/dts/rk3399-rock-pi-4a.dts
+++ b/arch/arm/dts/rk3399-rock-pi-4a.dts
@@ -12,3 +12,13 @@
 	model = "Radxa ROCK Pi 4A";
 	compatible = "radxa,rockpi4a", "radxa,rockpi4", "rockchip,rk3399";
 };
+
+&spi1 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <10000000>;
+	};
+};