arm64: dts: st: add stm32mp215f-dk board support

Add STM32MP215F Discovery Kit board support. It embeds a STM32MP235FAN SoC,
with 2GB of LPDDR4, 1*USB2 peripheral bus powered typeC, 1*ETH, wifi/BT
combo, LCD 18bit connector, CSI camera connector, ...

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250225-b4-stm32mp2_new_dts-v2-10-1a628c1580c7@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm64/boot/dts/st/Makefile

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 dtb-$(CONFIG_ARCH_STM32) += \
+	stm32mp215f-dk.dtb \
 	stm32mp235f-dk.dtb \
 	stm32mp257f-dk.dtb \
 	stm32mp257f-ev1.dtb

arch/arm64/boot/dts/st/stm32mp215f-dk.dts

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+/*
+ * Copyright (C) STMicroelectronics 2025 - All Rights Reserved
+ * Author: Amelie Delaunay <amelie.delaunay@foss.st.com> for STMicroelectronics.
+ */
+
+/dts-v1/;
+
+#include "stm32mp215.dtsi"
+#include "stm32mp21xf.dtsi"
+
+/ {
+	model = "STMicroelectronics STM32MP215F-DK Discovery Board";
+	compatible = "st,stm32mp215f-dk", "st,stm32mp215";
+
+	aliases {
+		serial0 = &usart2;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory@80000000 {
+		device_type = "memory";
+		reg = <0x0 0x80000000 0x0 0x80000000>;
+	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		fw@80000000 {
+			compatible = "shared-dma-pool";
+			reg = <0x0 0x80000000 0x0 0x4000000>;
+			no-map;
+		};
+	};
+};
+
+&arm_wdt {
+	timeout-sec = <32>;
+	status = "okay";
+};
+
+&usart2 {
+	status = "okay";
+};