add UTC tag to date string so users are aware of the time offset

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6112 65c4cc65-6c06-0410-ace0-fbb531ad65f3

build_tools/make_build_h

@@ -14,7 +14,7 @@ cat << END
 #define BUILD_KERNEL "${KERNEL}"
 #define BUILD_MACHINE "${MACHINE}"
 #define BUILD_OS "${OS}"
-#define BUILD_DATE "${DATE}"
+#define BUILD_DATE "${DATE} UTC"
 #define BUILD_USER "${USER}"
 
 END