i965: Set lower_vote_trivial in vector_nir_options_gen6 too.

There's a second struct for Gen6+.

Reviewed-by: Matt Turner <mattst88@gmail.com>

src/intel/compiler/brw_compiler.c

@@ -99,6 +99,7 @@ static const struct nir_shader_compiler_options vector_nir_options_gen6 = {
    .lower_unpack_unorm_2x16 = true,
    .lower_extract_byte = true,
    .lower_extract_word = true,
+   .lower_vote_trivial = true,
    .max_unroll_iterations = 32,
 };