Update VC-1 SP/MP range reduction documentation.
Update VC-1 SP/MP range reduction documentation.

mosterta/libvdpau,emericg/libvdpau-vp8,mosterta/libvdpau,emericg/libvdpau-vp8,Distrotech/libvdpau,Distrotech/libvdpau,Distrotech/libvdpau,emericg/libvdpau-vp8,mosterta/libvdpau