Fix texture caching when clut parameters change

Was only validating 2 bits of the clut format, d'oh.  Seems so obvious now.

So now it just includes the full clutformat in the hash, which fixes that problem nicely.  Since only clutformat and the loaded clut matter at that point, I removed it from the struct to slim it down a bit.

Thanks a lot to @daniel229 for help figuring it out.

-[Unknown]