Disable ML-based tx split pruning for bit-depth other than 8
Disable ML-based tx split pruning for bit-depth other than 8

Need some testing and tuning for 10/12-bit settings.

Change-Id: Ib136626965984c060776b3b5a2514540b3758fbd

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