libpayload: use PRIu64 type to print u64

The appropriate way to print a u64 variable regardless of the current
architecture is to use the PRI*64 macros.  libpayload is mostly used
in 32 bits but when ported to other projects and compiled in 64 bits
it breaks the compilation.

Change-Id: I479fd701f992701584d77d43c5cd5910f5ab7633
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45628
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/drivers/options.c

@@ -26,8 +26,11 @@
  * SUCH DAMAGE.
  */
 
+#define __STDC_FORMAT_MACROS
+
 #include <libpayload.h>
 #include <coreboot_tables.h>
+#include <inttypes.h>
 
 u8 *mem_accessor_base;
 
@@ -325,7 +328,7 @@ int get_option_as_string(const struct nvram_accessor *nvram, struct cb_cmos_opti
 			/* only works on little endian.
 			   26 bytes is enough for a 64bit value in decimal */
 			*dest = malloc(26);
-			sprintf(*dest, "%llu", *(u64*)raw);
+			sprintf(*dest, "%" PRIu64, *(u64 *)raw);
 			break;
 		case 's':
 			*dest = strdup(raw);