[lavapipe] Fix build error, missing input

Change-Id: If61fbc261353d10dea552ec4e21700483a77cd70
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/mesa/+/1006673
Reviewed-by: John Bauman <jbauman@google.com>
Commit-Queue: John Rosasco <rosasco@google.com>