ASoC: rt5677: Add DAPM audio path for hotword stream

Add a DAPM audio path from "DMIC L1" to "DSP Buffer" so that
when hotwording is enabled, DAPM does not power off the codec
with SND_SOC_BIAS_OFF.

Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Link: https://lore.kernel.org/r/20191106011335.223061-5-cujomalainey@chromium.org


Signed-off-by: Mark Brown <broonie@kernel.org>