iris: Clear ::has_hiz when disabling aux

Fixes: 2cddc953cd ("iris: some initial HiZ bits")
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/gallium/drivers/iris/iris_resource.c

@@ -293,6 +293,7 @@ iris_resource_disable_aux(struct iris_resource *res)
    res->aux.usage = ISL_AUX_USAGE_NONE;
    res->aux.possible_usages = 1 << ISL_AUX_USAGE_NONE;
    res->aux.sampler_usages = 1 << ISL_AUX_USAGE_NONE;
+   res->aux.has_hiz = 0;
    res->aux.surf.size_B = 0;
    res->aux.bo = NULL;
    res->aux.clear_color_bo = NULL;