gallivm: disable brilinear for lod bias and explicit lod.

This allows GL 4.5 CTS to pass in full with no flags, other than
that I'm not sure if it's a good or bad idea.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Cc: mesa-stable@lists.freedesktop.org
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6638>
3 files changed