due to upstream bloat, these no longer fit. it will have to be
fixed in the next libreboot release

memtest can't fit in such tiny space alongside SeaBIOS

The configs were enabling SeaBIOS payload, but this is to be
handled by lbmk, not coreboot.

Further, they were enabling VGA ROM execution in coreboot, but
this should be handled by SeaBIOS.

This board should not have a GRUB payload enabled either; this
will be checked and fixed if necessary in the next commit.

Add a build for QEMU AArch64 virtual machine using U-Boot as payload.
Coreboot config is based on the following defconfig:

    CONFIG_CBFS_SIZE=0x00c00000
    CONFIG_BOARD_EMULATION_QEMU_AARCH64=y
    CONFIG_CONSOLE_CBMEM_BUFFER_SIZE=0x20000
    CONFIG_COREBOOT_ROMSIZE_KB_12288=y
    CONFIG_UART_PCI_ADDR=0x0

The resulting ROM can be booted with a command line like:

    qemu-system-aarch64 \
        -machine virt,secure=on,virtualization=on \
        -cpu cortex-a53 -m 1G \
        -vga none -display none -serial stdio \
        -bios bin/qemu_arm64_12mb/uboot_*.rom

However, this is little more than a proof of concept because U-Boot
upstream is missing coreboot integration on non-x86 boards, which could
have been useful for e.g. a framebuffer.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>

U-Boot doesn't run on this board when this SuperIO serial driver is
disabled. Enable it.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>

Add a U-Boot build for the qemu_x86_12mb board. The config is a copy of
the upstream "coreboot" defconfig, but with OF_EMBED=y.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>

e.g.

./ifdtool --nuke me coreboot.rom

this will be used by rom release build scripts, to scrub
stuff like intel me from the rom