cbordump: Fix build with linux-clang-libc++

../cbordump/main.cpp:716:15: error: use of undeclared identifier 'LC_ALL'
    setlocale(LC_ALL, "C");
              ^

Change-Id: Ibff2345ffa99894cdcd48323f8c365d01ebd6300
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

examples/corelib/serialization/cbordump/main.cpp

@@ -56,6 +56,7 @@
 #include <QLocale>
 #include <QStack>
 
+#include <locale.h>
 #include <math.h>
 #include <stdarg.h>
 #include <stdio.h>