boards: arm: efm32pg_stk3401a: Convert to v2

Converts the board to hwmv2

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

boards/silabs/efm32pg_stk3401a/Kconfig.defconfig

@@ -5,9 +5,6 @@
 
 if BOARD_EFM32PG_STK3401A
 
-config BOARD
-	default "efm32pg_stk3401a" if BOARD_EFM32PG_STK3401A
-
 config CMU_HFXO_FREQ
 	default 40000000
 

boards/silabs/efm32pg_stk3401a/Kconfig.efm32pg_stk3401a

@@ -4,6 +4,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 config BOARD_EFM32PG_STK3401A
-	bool "SiLabs EFM32PG-STK3401A (Pearl Gecko)"
-	depends on SOC_SERIES_EFM32PG1B
 	select SOC_PART_NUMBER_EFM32PG1B200F256GM48

boards/silabs/efm32pg_stk3401a/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: efm32pg_stk3401a
+  vendor: silabs
+  socs:
+  - name: efm32pg1b200f256gm48

boards/silabs/efm32pg_stk3401a/efm32pg_stk3401a_defconfig

@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_SOC_SERIES_EFM32PG1B=y
-CONFIG_BOARD_EFM32PG_STK3401A=y
 CONFIG_ARM_MPU=y
 CONFIG_CONSOLE=y
 CONFIG_UART_CONSOLE=y