util: add missing include to build_id.h

Required to use uint8_t

Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
diff --git a/src/util/build_id.h b/src/util/build_id.h
index 86d611d..1872ca5 100644
--- a/src/util/build_id.h
+++ b/src/util/build_id.h
@@ -26,6 +26,8 @@
 
 #ifdef HAVE_DL_ITERATE_PHDR
 
+#include <stdint.h>
+
 struct build_id_note;
 
 const struct build_id_note *