boards: Convert stm32u5a9j_dk to HWM v2

Port the board to HWMv2.

Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>

boards/boards_legacy/arm/stm32u5a9j_dk/Kconfig.board

@@ -1,8 +0,0 @@
-# STM32U5A9J Discovery Kit board configuration
-
-# Copyright (c) 2023 STMicroelectronics
-# SPDX-License-Identifier: Apache-2.0
-
-config BOARD_STM32U5A9J_DK
-	bool "STM32U5A9J Discovery Kit Development Board"
-	depends on SOC_STM32U5A9XX

boards/boards_legacy/arm/stm32u5a9j_dk/Kconfig.defconfig

@@ -1,11 +0,0 @@
-# STM32U5A9J DISCOVERY KIT board configuration
-
-# Copyright (c) 2023 STMicroelectronics
-# SPDX-License-Identifier: Apache-2.0
-
-if BOARD_STM32U5A9J_DK
-
-config BOARD
-	default "stm32u5a9j_dk"
-
-endif # BOARD_STM32U5A9J_DK

boards/st/stm32u5a9j_dk/Kconfig.stm32u5a9j_dk

@@ -0,0 +1,5 @@
+# Copyright (c) 2023 STMicroelectronics
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_STM32U5A9J_DK
+	select SOC_STM32U5A9XX

boards/st/stm32u5a9j_dk/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: stm32u5a9j_dk
+  vendor: st
+  socs:
+    - name: stm32u5a9xx

boards/st/stm32u5a9j_dk/doc/index.rst

@@ -87,7 +87,7 @@ hardware features:
 Other hardware features have not been enabled yet for this board.
 
 The default configuration per core can be found in the defconfig file:
-``boards/arm/stm32u5a9j_dk/stm32u5a9j_dk_defconfig``
+:zephyr_file:`boards/st/stm32u5a9j_dk/stm32u5a9j_dk_defconfig`
 
 Pin Mapping
 ===========

boards/st/stm32u5a9j_dk/stm32u5a9j_dk_defconfig

@@ -1,10 +1,6 @@
 # Copyright (c) 2023 STMicroelectronics
 # SPDX-License-Identifier: Apache-2.0
 
-# Set SoC present on the board
-CONFIG_SOC_SERIES_STM32U5X=y
-CONFIG_SOC_STM32U5A9XX=y
-
 # Enable MPU
 CONFIG_ARM_MPU=y