boards: gd32f450z_eval: convert to HWMv2

Convert the board to HWMv2.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

boards/arm/gd32f450z_eval/Kconfig.board

@@ -1,6 +0,0 @@
-# Copyright (c) 2022, Rtone.
-# SPDX-License-Identifier: Apache-2.0
-
-config BOARD_GD32F450Z_EVAL
-	bool "GigaDevice GD32F450Z-EVAL"
-	depends on SOC_GD32F450

boards/arm/gd32f450z_eval/Kconfig.defconfig

@@ -1,9 +0,0 @@
-# Copyright (c) 2022, Rtone.
-# SPDX-License-Identifier: Apache-2.0
-
-if BOARD_GD32F450Z_EVAL
-
-config BOARD
-	default "gd32f450z_eval"
-
-endif # BOARD_GD32F450Z_EVAL

boards/v2/gd/gd32f450z_eval/Kconfig.gd32f450z_eval

@@ -0,0 +1,5 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_GD32F450Z_EVAL
+	select SOC_GD32F450

boards/v2/gd/gd32f450z_eval/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: gd32f450z_eval
+  vendor: GigaDevice Semiconductor
+  socs:
+    - name: gd32f450

boards/v2/gd/gd32f450z_eval/gd32f450z_eval_defconfig

@@ -1,10 +1,6 @@
 # Copyright (c) 2022, Rtone.
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_SOC_SERIES_GD32F4XX=y
-CONFIG_SOC_GD32F450=y
-CONFIG_BOARD_GD32F450Z_EVAL=y
-
 CONFIG_ARM_MPU=y
 CONFIG_HW_STACK_PROTECTION=y