dts: arm: st: u5: add support for stm32u5g9

Add device tree support for STM32U5G9 line.

Signed-off-by: Charles Dias <[email protected]>

Author: CharlesDias

Diff for: dts/arm/st/u5/stm32u5g9.dtsi

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 Charles Dias
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <st/u5/stm32u595.dtsi>
+
+/ {
+	soc {
+		compatible = "st,stm32u5g9", "st,stm32u5", "simple-bus";
+	};
+};

Diff for: dts/arm/st/u5/stm32u5g9Xj.dtsi

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2025 Charles Dias
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <mem.h>
+#include <st/u5/stm32u5g9.dtsi>
+
+/ {
+	sram0: memory@20000000 {
+		/* SRAM1 + SRAM2 + SRAM3 + SRAM5 + SRAM6 */
+		/* 768K + 64K + 832K + 832K + 512 */
+		reg = <0x20000000 DT_SIZE_K(3008)>;
+	};
+
+	sram4: memory@28000000 {
+		/* SRAM4, low-power background autonomous mode */
+		reg = <0x28000000 DT_SIZE_K(16)>;
+	};
+
+	soc {
+		flash-controller@40022000 {
+			flash0: flash@8000000 {
+				reg = <0x08000000 DT_SIZE_M(4)>;
+			};
+		};
+	};
+};