exynos: audiohal: Add missing USB device type for callmode device selection

* Allows to use usb headset for calls

Change-Id: I8a058711e2aaf320e35816795bee78db1db8a826
diff --git a/libaudio/audiohal/audio_hw.c b/libaudio/audiohal/audio_hw.c
index 7a9f786..a9b5541 100644
--- a/libaudio/audiohal/audio_hw.c
+++ b/libaudio/audiohal/audio_hw.c
@@ -549,6 +549,7 @@
                 case AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT:
                     break;
                 case AUDIO_DEVICE_OUT_USB_DEVICE:
+                case AUDIO_DEVICE_OUT_USB_HEADSET:
                     ret = DEVICE_USB_HEADSET;
                     break;
                 case AUDIO_DEVICE_OUT_LINE: