arm64: dts: rockchip: Add rock-5b board

Add board file for the RK3588 Rock 5B board. This is a basic
implementation which just brings up the eMMC and UART which is
enough to successfully boot Linux.

The ethernet controller is connected via PCIe so support will
come in a follow-up patch.
Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Reviewed-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230109155801.51642-8-sebastian.reichel@collabora.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/Makefile

@@ -87,4 +87,5 @@ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-odroid-m1.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-radxa-e25.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3568-rock-3a.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-evb1-v10.dtb
+dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588-rock-5b.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3588s-rock-5a.dtb

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

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+/dts-v1/;
+
+#include "rk3588.dtsi"
+
+/ {
+	model = "Radxa ROCK 5 Model B";
+	compatible = "radxa,rock-5b", "rockchip,rk3588";
+
+	aliases {
+		mmc1 = &sdhci;
+		serial2 = &uart2;
+	};
+
+	chosen {
+		stdout-path = "serial2:1500000n8";
+	};
+
+	vcc5v0_sys: vcc5v0-sys-regulator {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc5v0_sys";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+	};
+};
+
+&sdhci {
+	bus-width = <8>;
+	no-sdio;
+	no-sd;
+	non-removable;
+	max-frequency = <200000000>;
+	mmc-hs400-1_8v;
+	mmc-hs400-enhanced-strobe;
+	status = "okay";
+};
+
+&uart2 {
+	pinctrl-0 = <&uart2m0_xfer>;
+	status = "okay";
+};