ASoC: dmaengine-pcm: Add support for platforms which can't report residue

Unfortunately there are still quite a few platforms with a dmaengine driver
which do not support reporting the number of bytes left to transfer. If we want
to support these platforms in the generic dmaengine PCM driver we have.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index 1a7897a..e705286 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -86,6 +86,11 @@
  * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
  */
 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
+/*
+ * The platforms dmaengine driver does not support reporting the ammount of
+ * bytes that are still left to transfer.
+ */
+#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)
 
 /**
  * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM