build: allow builds against GStreamer 1.7.x
build: allow builds against GStreamer 1.7.x

Signed-off-by: Víctor Manuel Jáquez Leal <4955886a7d0bd82ff6afce9ed1e93fbb85ab8088@intel.com>

gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi