panvk: add support for {s,u}dot_4x8_{sat}

Generate IDPADD instruction to support integer dot product
Support is added for both signed/unsigned dot product as well as
saturated dot product.
Support is only for v9+.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34812>
4 files changed