panfrost: Don't mask coverage mask to 4-bits

While it is correct for MSAA 4x, it will break for MSAA 8x and 16x, and
it is only dubiously correct for no-MSAA. Drop the mask.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6195>
2 files changed