lavd/qtkit: Silence deprecation warnings when using clang.

Reviewed-by: Thilo Borgmann

libavdevice/qtkit.m

@@ -25,6 +25,10 @@
  * @author Vadim Kalinsky <vadim@kalinsky.ru>
  */
 
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
 #import <QTKit/QTKit.h>
 #include <pthread.h>