panfrost: Take the number of samples into account in blend shaders

Midgard has to split the writeout instruction if the number of bits per
pixel exceeds 128. We thus need to take the number of samples into
account when creating blend shaders.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7984>
5 files changed