APs use a lot less stack, so set up a separate stack for those in .bss.
Now that CPU_INFO_V2 is the only code path that is used, there is no
need to align stacks in c_start.S.
Change-Id: I7a681a2e3003da0400843daa5d6d6180d952abf5
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69123
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>