hal: Add support for VoWLAN feature

Add VoWLAN pcm id, usecase to enable voice
over WLAN feature.

Change-Id: I2d10ff06342bfcbef15a4769ba90deaeb4218107
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 205977b..a6824c1 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -80,6 +80,7 @@
     USECASE_VOICE2_CALL,
     USECASE_VOLTE_CALL,
     USECASE_QCHAT_CALL,
+    USECASE_VOWLAN_CALL,
     USECASE_COMPRESS_VOIP_CALL,
 
     USECASE_INCALL_REC_UPLINK,