radeonsi: don't cache FMASK transactions from CB in L2

radeonsi: don't cache FMASK transactions from CB in L2

FMASK is usually pretty large. It's better to leave the cache to shaders.
FMASK stores are still cached, but they can be evicted sooner, which is
the same as other color stores. Only DCC, HTILE, and CMASK are cached.

I haven't benchmarked this, but it seems like the right thing to do.
This only affected APUs.

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10003>