yukawa: Fix set_voice_volume() support

cherry-picked from AOSP SHA aa16ebabc7e4ed1c7fbf045abb7da43b99c93113

Merged-In: Ieb92c9b70bcf43957f2a66bed19e3b875ee46c6b

Bug: 152625706

Test: Tested on AOSP, see above SHA for details.
Change-Id: I553e0ea05f538a0cfb06a07415bff591f70c6cd1
diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index 4f6a652..d145b42 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -849,7 +849,7 @@
 static int adev_set_voice_volume(struct audio_hw_device *dev, float volume)
 {
     ALOGV("adev_set_voice_volume: %f", volume);
-    return 0;
+    return -ENOSYS;
 }
 
 static int adev_set_master_volume(struct audio_hw_device *dev, float volume)