Make sure that the Pre-Op register is cleared when an atomic cycle has been finished without errors. Change-Id: Ied88337125b125474b411e2f39f668171d15bfac Signed-off-by: Werner Zeh <werner.zeh@siemens.com> Reviewed-on: https://review.coreboot.org/c/29634 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: David Hendricks <david.hendricks@gmail.com>