It's unsupported because small bitsizes are still not completely
supported. It should have been disabled by default with ACO.
Acked-by: Daniel Schürmann <daniel@schuermann.dev> Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4549>