x86: Modify config-file for Celsius-W420 to be consistent with huge tables.

Align the hypervisor region on a 2M boundary to avoid having to map it with
4K pages.

Signed-off-by: Ivan Kolchin <ivan.kolchin@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>