image: add support for raw YUY2/UYVY image copies.
image: add support for raw YUY2/UYVY image copies.

Implement raw image copies for YUY2 format. Add support for UYVY format
too, with the same copy function as for YUY2. Even though components
ordering differs, copying line strides is essentially the same.

https://bugzilla.gnome.org/show_bug.cgi?id=703939
https://bugzilla.gnome.org/show_bug.cgi?id=703940

Signed-off-by: Gwenole Beauchesne <729713629d9640cc095f1c77c692e1881f8093c4@intel.com>

gbeauchesne/gstreamer-vaapi,CapOM/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,GStreamer/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,ceyusa/gstreamer-vaapi,CapOM/gstreamer-vaapi,GStreamer/gstreamer-vaapi,ceyusa/gstreamer-vaapi,CapOM/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,gbeauchesne/gstreamer-vaapi