Deal with incomplete topologies, this patch restores sound on user
devices.

Fixes: daa480bd ("ASoC: soc-core: tidyup for snd_soc_dapm_add_routes()")
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: ojab // <ojab@ojab.ru>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/20200309192744.18380-3-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>