boards: Convert nucleo_wba55cg to HWM v2

Port the board to HWMv2.

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>

boards/boards_legacy/arm/nucleo_wba55cg/Kconfig.board

@@ -1,8 +0,0 @@
-# STM32WBA55CG Nucleo board configuration
-
-# Copyright (c) 2023 STMicroelectronics
-# SPDX-License-Identifier: Apache-2.0
-
-config BOARD_NUCLEO_WBA55CG
-	bool "Nucleo WBA55CG Development Board"
-	depends on SOC_STM32WBA55XX

boards/st/nucleo_wba55cg/Kconfig.defconfig

@@ -6,9 +6,6 @@
 
 if BOARD_NUCLEO_WBA55CG
 
-config BOARD
-	default "nucleo_wba55cg"
-
 config SPI_STM32_INTERRUPT
 	default y
 	depends on SPI

boards/st/nucleo_wba55cg/Kconfig.nucleo_wba55cg

@@ -0,0 +1,5 @@
+# Copyright (c) 2023 STMicroelectronics
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_NUCLEO_WBA55CG
+	select SOC_STM32WBA55XX

boards/st/nucleo_wba55cg/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: nucleo_wba55cg
+  vendor: st
+  socs:
+    - name: stm32wba55xx

boards/st/nucleo_wba55cg/nucleo_wba55cg_defconfig

@@ -1,9 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) 2023 STMicroelectronics
 
-CONFIG_SOC_SERIES_STM32WBAX=y
-CONFIG_SOC_STM32WBA55XX=y
-
 # enable uart driver
 CONFIG_SERIAL=y