[PVQ] Delete leftover code
[PVQ] Delete leftover code

Deletng the code since it is in fact for the PVQ, not for dist-8x8.

The relavant code removal for PVQ is commit:
d0b77ac7de2831cd52c7c1291977e331c79958c0
"Remove PVQ code" on 2017-10-20, which has removed the PVQ code.

Change-Id: I6b58d0acedb6bf278f35ac6c76a7a0a481cd3edb

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom