tu: Fix static blend bandwidth calculation

We were never setting the valid bit, so would never happen. If it did
happen, we forgot to merge in the bandwidth calculation from child
libraries.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33902>

src/freedreno/vulkan/tu_pipeline.cc

@@ -2109,6 +2109,9 @@ tu_pipeline_builder_parse_libraries(struct tu_pipeline_builder *builder,
          pipeline->prim_order = library->base.prim_order;
       }
 
+      if (library->base.bandwidth.valid)
+         pipeline->bandwidth = library->base.bandwidth;
+
       pipeline->set_state_mask |= library->base.set_state_mask;
 
       u_foreach_bit (i, library->base.set_state_mask) {
@@ -2896,6 +2899,8 @@ tu_calc_bandwidth(struct tu_bandwidth *bandwidth,
             vk_format_to_pipe_format(rp->stencil_attachment_format),
             UTIL_FORMAT_COLORSPACE_ZS, 1) / 8;
    }
+
+   bandwidth->valid = true;
 }
 
 /* Return true if the blend state reads the color attachments. */