cbfstool/fit: need inttypes.h for PRIx64

This is causing coreboot build in Chromium OS to fail.

BUG=None
TEST=emerge-eve coreboot
BRANCH=none

Change-Id: I4faa140b3046651b4ed0a9aeefe437048c6ef0da
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33780
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

util/cbfstool/fit.c

@@ -15,6 +15,7 @@
  * GNU General Public License for more details.
  */
 
+#include <inttypes.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>