radv: enable lower_mul_2x32_64

Fixes: 58bcebd987 ("spirv: Allow [i/u]mulExtended to use new nir opcode")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/vulkan/radv_shader.c

@@ -71,6 +71,7 @@ static const struct nir_shader_compiler_options nir_options = {
 	.lower_extract_word = true,
 	.lower_ffma = true,
 	.lower_fpow = true,
+	.lower_mul_2x32_64 = true,
 	.max_unroll_iterations = 32
 };