- Simplify stack size determination: MAX_CPUS * STACK_SIZE

- Check that this doesn't run into vga/oprom/bios area at link time
- Avoid overly complicated and not well understood hack which avoids that
  area by leaving a hole in the stack area.
- Adapt technexion/tim5690 to put ramstage at 1MB

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Myles Watson <mylesgw@gmail.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5181 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1