ASoC: Intel: add drain_notify support

This patch adds the support to implement drain_notify in Intels mfld driver

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/intel/sst-mfld-platform.h b/sound/soc/intel/sst-mfld-platform.h
index 3ea4fee..6c5e7dc 100644
--- a/sound/soc/intel/sst-mfld-platform.h
+++ b/sound/soc/intel/sst-mfld-platform.h
@@ -104,6 +104,8 @@
 struct sst_compress_cb {
 	void *param;
 	void (*compr_cb)(void *param);
+	void *drain_cb_param;
+	void (*drain_notify)(void *param);
 };
 
 struct compress_sst_ops {