Fixed YUV overlay code for Quicktime 6

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40501

src/video/quartz/SDL_QuartzVideo.m

@@ -1472,7 +1472,7 @@ static SDL_Overlay* QZ_CreateYUVOverlay (_THIS, int width, int height,
     (**yuv_idh).frameCount = 1;
     (**yuv_idh).clutID = -1;
     (**yuv_idh).dataSize = 0;
-    (**yuv_idh).depth = 12;
+    (**yuv_idh).depth = 24;
     
     HUnlock ((Handle)yuv_idh);