vp9-svc: Fix to disable cyclic refresh on key superframes.
vp9-svc: Fix to disable cyclic refresh on key superframes.

Cyclic refresh is disabled on key frames, but we did not
disable it for for spatial layers whose base is a key frame
(i.e., on a key-superframe).

This fix means generally somewhat lower frame-level QP will be
used for those spatial layers whose base is a key frame,
which will generally mean little better quality for the
key-superframes.

Change-Id: Idf090651aa2f5856fb6696c89198a9f6d5d50280

ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx