freedreno: allow FMT6_8_UNORM as a UBWC format
FMT6_8_UNORM is necessary for NV12 textures.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
FMT6_8_UNORM is necessary for NV12 textures.