arch/x86: Prepare GDT for x86_64

Make GDT a separate table and don't reuse GDT descriptor as unused
first field of GDT.

Required for separate x86_64 GDT descriptor, pointing to the same
GDT.

Tested on qemu.

Change-Id: I513329b67d49ade1055bc07cf7b93ff2e0131e0b
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31769
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions