x86: theadorable-x86-xxx_defconfig: Move VGA BIOS to make room for U-Boot

The build breaks because its not fitting the U-Boot binary into the ROM
image. So lets move VGA BIOS a bit to make room for the grown U-Boot
binary.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>