ASoC: wm_adsp: Support acknowledged controls

This patch handles publishing acknowledged controls through ALSA.
These controls allow user-side to send events to the firmware and
wait for the firmware to acknowledge it.

Note that although acked controls only operate in the direction
host->firmware, and therefore they are write-only as seen from user-
side code, we have to make them readable to account for all the code
out there that assumes that ALSA controls are always readable (amixer
for example.)

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/wmfw.h b/sound/soc/codecs/wmfw.h
index 892fc74..ec78b9d 100644
--- a/sound/soc/codecs/wmfw.h
+++ b/sound/soc/codecs/wmfw.h
@@ -27,6 +27,7 @@
 #define WMFW_CTL_FLAG_READABLE    0x0001
 
 /* Non-ALSA coefficient types start at 0x1000 */
+#define WMFW_CTL_TYPE_ACKED       0x1000 /* acked control */
 #define WMFW_CTL_TYPE_HOSTEVENT   0x1001 /* event control */
 
 struct wmfw_header {