Append fallthrough statement to fix warning reported during compilation.

Fixes: b80d19c1 ("ASoC: Intel: Restore Baytrail ADSP streams only when ADSP was in reset")
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20190828095102.15737-1-cezary.rojewski@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>