pan/mdg: Fix auxiliary load/store swizzle packing

It needs to respect the existing swizzle, as well as the type size.

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/6321>
3 files changed