ARM: defconfig: add unified config for RPi3 and RPi4

Provide a defconfig which allows us to boot Raspberrry Pi 4
and Raspberry Pi 3 Model B/B+
Instead of using the embedded DTB as done in RPi3 we use the
devicetree provided by the firmware.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>

arch/arm/mach-bcm283x/Kconfig

@@ -188,6 +188,13 @@ config TARGET_RPI_4
 	  This option creates a build targeting the ARMv8/AArch64 ISA.
 	select BCM2711_64B
 
+config TARGET_RPI_ARM64
+	bool "Raspberry Pi one binary 64-bit build"
+	help
+	  Support for all armv8 based Raspberry Pi variants, such as
+	  the RPi 4 model B, in AArch64 (64-bit) mode.
+	select ARM64
+
 endchoice
 
 config SYS_BOARD

configs/rpi_arm64_defconfig

@@ -0,0 +1,45 @@
+CONFIG_ARM=y
+CONFIG_ARM64=y
+CONFIG_TARGET_RPI_ARM64=y
+CONFIG_ARCH_BCM283X=y
+CONFIG_SYS_TEXT_BASE=0x00080000
+CONFIG_SYS_MALLOC_F_LEN=0x2000
+CONFIG_DISTRO_DEFAULTS=y
+CONFIG_NR_DRAM_BANKS=2
+CONFIG_OF_BOARD_SETUP=y
+CONFIG_USE_PREBOOT=y
+CONFIG_PREBOOT="usb start"
+CONFIG_MISC_INIT_R=y
+# CONFIG_DISPLAY_CPUINFO is not set
+# CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_SYS_PROMPT="U-Boot> "
+# CONFIG_CMD_FLASH is not set
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_FS_UUID=y
+CONFIG_OF_BOARD=y
+CONFIG_ENV_FAT_INTERFACE="mmc"
+CONFIG_ENV_FAT_DEVICE_AND_PART="0:1"
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
+CONFIG_DM_KEYBOARD=y
+CONFIG_DM_MMC=y
+CONFIG_MMC_SDHCI=y
+CONFIG_MMC_SDHCI_BCM2835=y
+CONFIG_PHYLIB=y
+CONFIG_DM_ETH=y
+CONFIG_PINCTRL=y
+# CONFIG_PINCTRL_GENERIC is not set
+# CONFIG_REQUIRE_SERIAL_CONSOLE is not set
+CONFIG_USB=y
+CONFIG_DM_USB=y
+CONFIG_USB_DWC2=y
+CONFIG_USB_KEYBOARD=y
+CONFIG_USB_HOST_ETHER=y
+CONFIG_USB_ETHER_LAN78XX=y
+CONFIG_USB_ETHER_SMSC95XX=y
+CONFIG_DM_VIDEO=y
+CONFIG_SYS_WHITE_ON_BLACK=y
+CONFIG_CONSOLE_SCROLL_LINES=10
+CONFIG_PHYS_TO_BUS=y
+CONFIG_OF_LIBFDT_OVERLAY=y