pan/bi: Add format field to IR

To make register_format packing explicit, and possibly in the future
support the auto mode.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6749>
4 files changed