fix(uuid): add missing `#include` directives

These include directives were missing from both `uuid.h` files.

Change-Id: I875dfda3e0985728277b72f0e7597dde5cf9d304
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/include/tools_share/uuid.h b/include/tools_share/uuid.h
index 2ced3a3..3445f20 100644
--- a/include/tools_share/uuid.h
+++ b/include/tools_share/uuid.h
@@ -27,13 +27,15 @@
  */
 
 /*
- * Portions copyright (c) 2014-2020, ARM Limited and Contributors.
+ * Portions copyright (c) 2014-2023, Arm Limited and Contributors.
  * All rights reserved.
  */
 
 #ifndef UUID_H
 #define UUID_H
 
+#include <stdint.h>
+
 /* Length of a node address (an IEEE 802 address). */
 #define	_UUID_NODE_LEN		6