board: rockchip: Add the Turing RK1 SoM

The Turing RK1 is a Rockchip RK3588 based SoM from Turing Machines.

Specifications:

    Rockchip RK3588 SoC
    4x ARM Cortex-A76, 4x ARM Cortex-A55
    8/16/32GB memory LPDDR4x
    Mali G610MC4 GPU
    32GB eMMC HS400
    2x USB 2.0, 2x USB 3.0
    2x MIPI CSI 4x lanes
    1x MIPI-DSI DPHY 2x lanes
    PCIe 2.0 x1, PCIe 3.0 x4
    1x HDMI 2.1 output, 1x DP 1.4 output
    Gigabit Ethernet
    Size: 69.6mm x 45mm (260-pin SO-DIMM connector)

Kernel commit:
2806a69f3fef ("arm64: dts: rockchip: Add Turing RK1 SoM support")

Signed-off-by: Joshua Riek <jjriek@verizon.net>
Tested-by: Sam Edwards <CFSworks@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3588-turing-rk1-u-boot.dtsi b/arch/arm/dts/rk3588-turing-rk1-u-boot.dtsi
new file mode 100644
index 0000000..06c6f32
--- /dev/null
+++ b/arch/arm/dts/rk3588-turing-rk1-u-boot.dtsi
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2023 Joshua Riek <jjriek@verizon.net>
+ *
+ */
+
+#include "rk3588-u-boot.dtsi"
+
+/ {
+	chosen {
+		u-boot,spl-boot-order = "same-as-spl", &sdmmc, &sdhci;
+	};
+};
+
+&sdhci {
+	cap-mmc-highspeed;
+	mmc-ddr-1_8v;
+	mmc-hs200-1_8v;
+};
+
+&uart9 {
+	bootph-pre-ram;
+	clock-frequency = <24000000>;
+	status = "okay";
+};