hal: Adding Pan-Scale, downmix mixer control support.

Add support in HAL to send mix matrix params using downmix,
Pan-Scale mixer controls. Add new interactive usecases and
also add support to open and teardown for interactive streams.
Add support in test app for supporting up to 9 concurrent
streams. Add support for mixer matrix params handling.

Change-Id: I0dc5b908ee779b2b2c526a67609c057f591f26e7
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index 33edf75..f4d60c2 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -465,6 +465,15 @@
 #define TRANSCODE_LOOPBACK_RX_DEV_ID 43
 #define TRANSCODE_LOOPBACK_TX_DEV_ID 44
 
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE1 0
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE2 1
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE3 27
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE4 45
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE5 46
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE6 47
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE7 48
+#define PLAYBACK_INTERACTIVE_STRM_DEVICE8 49
+
 #ifdef PLATFORM_APQ8084
 #define FM_RX_VOLUME "Quat MI2S FM RX Volume"
 #elif PLATFORM_MSM8994