In order to use early serial output we need to enable P2SB BAR0, because that allows PCR access to PCH registers. TEST=tested on OCP Tioga Pass Change-Id: I476f90b2df67b8045582f0b72dd680dea5a9a275 Signed-off-by: Andrey Petrov <anpetrov@fb.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/39781 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>