util/sconfig: Add commonlib/helpers.h

Followup work injects ARRAY_SIZE() in static.c

Change-Id: Ifbcaa1b613aef312d3876e8b536499a9f01a8d19
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31932
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Martin Roth <martinroth@google.com>

util/sconfig/main.c

@@ -15,6 +15,7 @@
  */
 
 #include <ctype.h>
+#include <commonlib/helpers.h>
 #include "sconfig.h"
 #include "sconfig.tab.h"