board: rockchip: Add support for FriendlyARM NanoPi R2C Plus

The NanoPi R2C Plus is a small variant of NanoPi R2C with a on-board
eMMC flash (8G) included.

The device tree is taken from the kernel v6.5.

Signed-off-by: Tianling Shen <cnsztl@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3328-nanopi-r2c-plus.dts b/arch/arm/dts/rk3328-nanopi-r2c-plus.dts
new file mode 100644
index 0000000..16a1958
--- /dev/null
+++ b/arch/arm/dts/rk3328-nanopi-r2c-plus.dts
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Copyright (c) 2021 FriendlyElec Computer Tech. Co., Ltd.
+ * (http://www.friendlyarm.com)
+ *
+ * Copyright (c) 2023 Tianling Shen <cnsztl@gmail.com>
+ */
+
+/dts-v1/;
+#include "rk3328-nanopi-r2c.dts"
+
+/ {
+	model = "FriendlyElec NanoPi R2C Plus";
+	compatible = "friendlyarm,nanopi-r2c-plus", "rockchip,rk3328";
+
+	aliases {
+		mmc1 = &emmc;
+	};
+};
+
+&emmc {
+	bus-width = <8>;
+	cap-mmc-highspeed;
+	max-frequency = <150000000>;
+	mmc-ddr-1_8v;
+	mmc-hs200-1_8v;
+	non-removable;
+	pinctrl-names = "default";
+	pinctrl-0 = <&emmc_clk &emmc_cmd &emmc_bus8>;
+	vmmc-supply = <&vcc_io_33>;
+	vqmmc-supply = <&vcc18_emmc>;
+	status = "okay";
+};