v3dv: add support for BC1-3 compressed formats
Used by some apps like RBDOOM-3-BFG
Note that as we don't support all the BC formats, we will never be able to expose textureCompressedBC. But AFAIU the spect, nothing disallows to expose those formats. This is somewhat tricky for apps, as they would need to switch to check for the individual formats they use.