qaxtypefunctions.h: Fix build with headersclean check.

Add missing include qt_windows.h, required for
qtbase/ 6668f5becfb8fcb6d10e42495c6ea5cdba2d15c5.

Change-Id: I8e9ea48e950b210579cfc523fafea84300aaca22
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andy Shaw <andy.shaw@digia.com>

src/activeqt/shared/qaxtypefunctions.h

@@ -40,9 +40,7 @@
 #ifndef QAXTYPEFUNCTIONS_P_H
 #define QAXTYPEFUNCTIONS_P_H
 
-#if !defined(_WINDOWS_) && !defined(_WINDOWS_H) && !defined(__WINDOWS__)
-#error Must include windows.h first!
-#endif
+#include <QtCore/qt_windows.h>
 
 #include <QtGui/qcolor.h>
 #include <QtGui/qfont.h>