nvk: Use suld.constant for EDB uniform texel buffers

In 2183bc73a6 ("nvk: Use suld for EDB uniform texel buffers"), we
started using suld instead of tld for EDB uniform texel buffers because
we needed it for correctness.  However, it's slow as mud.  Using
suld.constant seems to fix the performance regression.  I don't know if
it's quite tld performance, but it's close.

Backport-to: 25.0
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33612>

src/nouveau/vulkan/nvk_nir_lower_descriptors.c

@@ -1238,6 +1238,8 @@ lower_edb_buffer_tex_instr(nir_builder *b, nir_tex_instr *tex,
                                              .image_dim = GLSL_SAMPLER_DIM_BUF,
                                              .image_array = false,
                                              .format = PIPE_FORMAT_NONE,
+                                             .access = ACCESS_NON_WRITEABLE |
+                                                       ACCESS_CAN_REORDER,
                                              .dest_type = tex->dest_type);
       if (tex->is_sparse) {
          nir_intrinsic_instr *intr = nir_instr_as_intrinsic(res->parent_instr);