nak: Set TLS size properly in the shader header

We were only accounting for load/store_scratch before, not spilling.
Pull the value from the Shader, that one's accurate.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24998>

src/nouveau/compiler/nak.rs

@@ -496,7 +496,7 @@ pub extern "C" fn nak_compile_shader(
             ],
             smem_size: nir.info.shared_size.try_into().unwrap(),
         },
-        hdr: encode_hdr_for_nir(nir, nir.scratch_size),
+        hdr: encode_hdr_for_nir(nir, s.tls_size, fs_key),
     };
 
     let code = if nak.sm >= 75 {