soc/intel/common/block/smm/smihandler.c: shutdown on case intrusion

Signed-off-by: Michał Kopeć <michal@nozomi.space>

src/soc/intel/common/block/smm/smihandler.c

@@ -15,6 +15,7 @@
 #include <device/pci_def.h>
 #include <device/pci_ops.h>
 #include <elog.h>
+#include <halt.h>
 #include <intelblocks/fast_spi.h>
 #include <intelblocks/oc_wdt.h>
 #include <intelblocks/pmclib.h>
@@ -468,6 +469,7 @@ void smihandler_southbridge_tco(
 		 * If we ever get here, probably the case has been opened.
 		 */
 		printk(BIOS_CRIT, "Case intrusion detected.\n");
+		poweroff();
 	}
 }