Re-enabled CIImage based gfx video item on Mac

Also prefer CoreImageHandle to GLTextureHandle
in QuickTime player backend, to avoid unnecessary
copy via FBO.

Change-Id: Id5aa039c438378b7bbf816b7845b05574683c471
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>

src/multimediawidgets/multimediawidgets.pro

@@ -31,8 +31,7 @@ SOURCES += \
     qvideowidget.cpp
 
 mac {
-    # QtWidgets is not yet supported on Mac (!).
-    false:!simulator {
+    !simulator {
         PRIVATE_HEADERS += qpaintervideosurface_mac_p.h
         OBJECTIVE_SOURCES += qpaintervideosurface_mac.mm
     }