boards: Convert nucleo_l476rg to HWM v2

Port the board to HWMv2.

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

boards/boards_legacy/arm/nucleo_l476rg/Kconfig.board

@@ -1,9 +0,0 @@
-# STM32L476RG Nucleo board configuration
-
-# Copyright (c) 2016 Open-RnD Sp. z o.o.
-# Copyright (c) 2016 BayLibre, SAS
-# SPDX-License-Identifier: Apache-2.0
-
-config BOARD_NUCLEO_L476RG
-	bool "Nucleo L476RG Development Board"
-	depends on SOC_STM32L476XX

boards/st/nucleo_l476rg/Kconfig.defconfig

@@ -6,9 +6,6 @@
 
 if BOARD_NUCLEO_L476RG
 
-config BOARD
-	default "nucleo_l476rg"
-
 config SPI_STM32_INTERRUPT
 	default y
 	depends on SPI

boards/st/nucleo_l476rg/Kconfig.nucleo_l476rg

@@ -0,0 +1,5 @@
+# Copyright (c) 2016 BayLibre, SAS
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_NUCLEO_L476RG
+	select SOC_STM32L476XX

boards/st/nucleo_l476rg/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: nucleo_l476rg
+  vendor: st
+  socs:
+    - name: stm32l476xx

boards/st/nucleo_l476rg/doc/index.rst

@@ -127,7 +127,7 @@ The Zephyr nucleo_l476rg board configuration supports the following hardware fea
 Other hardware features are not yet supported on this Zephyr port.
 
 The default configuration can be found in the defconfig file:
-``boards/arm/nucleo_l476rg/nucleo_l476rg_defconfig``
+``boards/st/nucleo_l476rg/nucleo_l476rg_defconfig``
 
 
 Connections and IOs

boards/st/nucleo_l476rg/nucleo_l476rg_defconfig

@@ -1,8 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_SOC_SERIES_STM32L4X=y
-CONFIG_SOC_STM32L476XX=y
-
 # enable uart driver
 CONFIG_SERIAL=y