x86: Add support for passing tables into U-Boot

The EFI stub provides information to U-Boot in a table. This includes the
memory map which is needed to decide where to relocate U-Boot. Collect this
information in the early init code and store it in global_data.

Fix up the BIST code at the same time since we don't have it when booting
from EFI and can assume it is 0.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>