boards: arm64: rpi_4b: Convert to v2

Converts the board to hwmv2

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

boards/v2/raspberrypi/rpi_4b/Kconfig.defconfig

@@ -1,6 +1,2 @@
 # Copyright 2023 honglin leng <a909204013@gmail.com>
 # SPDX-License-Identifier: Apache-2.0
-
-config BOARD
-	default "Raspberry Pi 4 Model B"
-	depends on BOARD_RPI_4B

boards/v2/raspberrypi/rpi_4b/Kconfig.rpi_4b

@@ -2,5 +2,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 config BOARD_RPI_4B
-	bool "Broadcom BCM2711"
+	select SOC_BCM2711
-	depends on SOC_BCM2711

boards/v2/raspberrypi/rpi_4b/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: rpi_4b
+  vendor: Raspberry Pi
+  socs:
+  - name: bcm2711

boards/v2/raspberrypi/rpi_4b/rpi_4b_defconfig

@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # Platform Configuration
-CONFIG_SOC_BCM2711=y
-CONFIG_BOARD_RPI_4B=y
 CONFIG_ARM64_VA_BITS_36=y
 CONFIG_ARM64_PA_BITS_36=y