Audio: Fix HDMI audio device switch issue

- Device routing is not triggered in the following scenario:
  Start playback on HDMI, pause it, unplug and plug the HDMI cable,
  resume playback, music starts on speaker.
- Fix by update outputDesc->mDevice even if the requested device is 0

Change-Id: I4d1c1f76094f4acb20acdb8af68302ea8a1008c5
CRs-Fixed: 606004