hal: Allow hal to open Telephony RX as attached device

- Incall recording and USB voice call does not work as
  Telephony RX is not available device. It is default
  attached device and policy should be able to open input
  stream with this device.
- Change is to allow opening Telephony RX even if its
  not in call to serve as default attached device.

Change-Id: I239cede58141dfe3faf7f06a495cc2824f201a58