pan/blit: Compile blit shaders without IDVS

On Valhall, the fragment shader differs based on whether IDVS or the legacy
geometry flow is used be. In particular, varyings are accessed differently.

We use the legacy geometry flow for blitting on all GPUs, so indicate this in
the shader inputs.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16035>

src/panfrost/lib/pan_blitter.c

@@ -572,6 +572,7 @@ pan_blitter_get_blit_shader(struct panfrost_device *dev,
         struct panfrost_compile_inputs inputs = {
                 .gpu_id = dev->gpu_id,
                 .is_blit = true,
+                .no_idvs = true,
         };
         struct util_dynarray binary;