vp9: add fate test for segmentation image-edge issue.

Sample available at:
http://downloads.webmproject.org/test_data/libvpx/vp90-2-15-segkey_adpq.webm

tests/fate/vpx.mak

@@ -103,6 +103,7 @@ $(eval $(call FATE_VP9_SUITE,06-bilinear,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,09-lf_deltas,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,10-show-existing-frame,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,10-show-existing-frame2,$(1),$(2)))
+$(eval $(call FATE_VP9_SUITE,15-segkey_adpq,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,2pass-akiyo,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,parallelmode-akiyo,$(1),$(2)))
 $(eval $(call FATE_VP9_SUITE,segmentation-aq-akiyo,$(1),$(2)))