audio: add parameter for device shutdown notification

 - Add new define to receive device shutdown notification

Change-Id: I74c07de91d4eae5312b9ef609d218bdf45d61dc5
diff --git a/hal/audio_extn/pm.c b/hal/audio_extn/pm.c
index 7b76f60..b091723 100644
--- a/hal/audio_extn/pm.c
+++ b/hal/audio_extn/pm.c
@@ -33,12 +33,14 @@
 #include "pm.h"
 #include <cutils/log.h>
 
+/* Device state*/
+#define AUDIO_PARAMETER_KEY_DEV_SHUTDOWN "dev_shutdown"
+
 static s_audio_subsys audio_ss;
 
 int audio_extn_pm_vote(void)
 {
     int err, intfd, ret;
-    FILE *fd;
     enum pm_event subsys_state;
     char halPropVal[PROPERTY_VALUE_MAX];
     bool prop_unload_image = false;