boards: Convert nucleo_f303k8 to HWM v2

Port the board to HWMv2.

Signed-off-by: Abderrahmane Jarmouni <abderrahmane.jarmouni-ext@st.com>

boards/boards_legacy/arm/nucleo_f303k8/Kconfig.board

@@ -1,9 +0,0 @@
-# NUCLEO-32 F303k8 board configuration
-
-# Copyright (c) 2020 Sebastian Schwabe <sebastian.schwabe@mailbox.tu-dresden.de>
-#                    	Fabian Paschke <fabian.paschke@eas.iis.fraunhofer.de>
-# SPDX-License-Identifier: Apache-2.0
-
-config BOARD_NUCLEO_F303K8
-	bool "NUCLEO-32 F303K8 Development Board"
-	depends on SOC_STM32F303X8

boards/boards_legacy/arm/nucleo_f303k8/Kconfig.defconfig

@@ -1,12 +0,0 @@
-# NUCLEO-32 F303k8 board configuration
-
-# Copyright (c) 2020 Sebastian Schwabe <sebastian.schwabe@mailbox.tu-dresden.de>
-#                    	Fabian Paschke <fabian.paschke@eas.iis.fraunhofer.de>
-# SPDX-License-Identifier: Apache-2.0
-
-if BOARD_NUCLEO_F303K8
-
-config BOARD
-	default "nucleo_f303k8"
-
-endif # BOARD_NUCLEO_F303K8

boards/st/nucleo_f303k8/Kconfig.nucleo_f303k8

@@ -0,0 +1,5 @@
+# Copyright (c) 2020 Sebastian Schwabe <sebastian.schwabe@mailbox.tu-dresden.de>
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_NUCLEO_F303K8
+	select SOC_STM32F303X8

boards/st/nucleo_f303k8/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: nucleo_f303k8
+  vendor: st
+  socs:
+    - name: stm32f303x8

boards/st/nucleo_f303k8/nucleo_f303k8_defconfig

@@ -1,8 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_SOC_SERIES_STM32F3X=y
-CONFIG_SOC_STM32F303X8=y
-
 CONFIG_SERIAL=y
 
 # console