anv: use a simpler MUE layout for fast linked libraries

anv: use a simpler MUE layout for fast linked libraries

The compaction introduced in a2521233631 ("intel/compiler/mesh: compactify MUE layout")
is not suitable for the case where graphics pipeline libraries are fast
linked, as the fragment shader won't receive the mue_map to know where
to locate its inputs.
For that case, keep doing what we did before and lay things down in the
order varyings are defined, which is also how it works for the non-mesh
case.

Fixes dEQP-VK.fragment_shading_rate.*fast_linked_library*.ms

Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25047>