audio hal: add support for USB_HEADSET device

Add support for USB_HEADSET device in device selection logic where
only USB_DEVICE was supported so far.

Bug: 36220140
Test: check music/video playback, voice/VoIP calls, OK google and
Camcorder with and without USB headset

Change-Id: Ia1a241b9a9cdec6c48c0596a057fabac30b1b16f