hal: Add support to enable VBat feature

Add support to enable VBat feature. This includes required changes
to select VBat speaker devices for audio and voice usecases and
sending the VBat calibration data to codec driver.

Change-Id: I2234bee3cc4d6f16934a4b27ef9da21cde74bb48
diff --git a/hal/msm8960/platform.c b/hal/msm8960/platform.c
index 6d2d478..b72cae9 100644
--- a/hal/msm8960/platform.c
+++ b/hal/msm8960/platform.c
@@ -373,7 +373,8 @@
     return 0;
 }
 
-void platform_add_backend_name(char *mixer_path, snd_device_t snd_device)
+void platform_add_backend_name(char *mixer_path, snd_device_t snd_device,
+                               struct audio_usecase *usecase)
 {
     if (snd_device == SND_DEVICE_IN_BT_SCO_MIC)
         strlcat(mixer_path, " bt-sco", MIXER_PATH_MAX_LENGTH);