audio: sndmonitor

Monitor sound card status and report online/offline
events back to the streams registered with it and
to audio_dev.

Bug: 30075678
Change-Id: Iea74d5c83f7fe92ba4a24f4f4650ce255bdb48e8
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index a6d9789..6179d01 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -2208,3 +2208,9 @@
     }
     return 0;
 }
+
+int platform_snd_card_update(void *platform __unsed,
+                             card_status_t status __unused)
+{
+    return -1;
+}