x86 romstage: Move stack just below RAMTOP

Placement of romstage stack in RAM was vulnerable for getting corrupted
by decompressed ramstage.

Change-Id: Ic032bd3e69f4ab8dab8e5932df39fab70aa3e769
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7096
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/soc/intel/baytrail/romstage/cache_as_ram.inc

@@ -18,7 +18,6 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <cpu/x86/stack.h>
 #include <cpu/x86/mtrr.h>
 #include <cpu/x86/cache.h>
 #include <cpu/x86/post_code.h>

src/soc/intel/fsp_baytrail/fsp/chipset_fsp_util.c

@@ -19,7 +19,6 @@
 
 #include <types.h>
 #include <string.h>
-#include <cpu/x86/stack.h>
 #include <console/console.h>
 #include <bootstate.h>
 #include <cbmem.h>