vp9_detokenize.c: remove unused macros
vp9_detokenize.c: remove unused macros

LOW_VAL_CONTEXT_NODE
TWO_CONTEXT_NODE
THREE_CONTEXT_NODE
HIGH_LOW_CONTEXT_NODE
CAT_ONE_CONTEXT_NODE
CAT_THREEFOUR_CONTEXT_NODE
CAT_THREE_CONTEXT_NODE
CAT_FIVE_CONTEXT_NODE

unused since:
adaec4d Speeding up decode_coeffs().

Change-Id: Id07d2b0b76ff0ee6ef40d1b7a8e085e5e9e4aa8d

ittiamvpx/libvpx-1,smarter/aom,webmproject/libvpx,mbebenita/aom,webmproject/libvpx,mwgoldsmith/vpx,webmproject/libvpx,luctrudeau/aom,ShiftMediaProject/libvpx,mwgoldsmith/libvpx,luctrudeau/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,ShiftMediaProject/libvpx,smarter/aom,Topopiccione/libvpx,webmproject/libvpx,smarter/aom,smarter/aom,GrokImageCompression/aom,mwgoldsmith/libvpx,ittiamvpx/libvpx-1,mbebenita/aom,ShiftMediaProject/libvpx,mwgoldsmith/vpx,mwgoldsmith/libvpx,luctrudeau/aom,mbebenita/aom,Topopiccione/libvpx,mwgoldsmith/vpx,Topopiccione/libvpx,ittiamvpx/libvpx-1,mwgoldsmith/libvpx,ittiamvpx/libvpx-1,webmproject/libvpx,mbebenita/aom,luctrudeau/aom,mwgoldsmith/vpx,mwgoldsmith/vpx,mbebenita/aom,smarter/aom,GrokImageCompression/aom,ShiftMediaProject/libvpx,Topopiccione/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx,mwgoldsmith/vpx,mwgoldsmith/libvpx,GrokImageCompression/aom,GrokImageCompression/aom,mbebenita/aom,webmproject/libvpx,Topopiccione/libvpx,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,ittiamvpx/libvpx-1,ittiamvpx/libvpx-1,mwgoldsmith/libvpx,luctrudeau/aom,mbebenita/aom