hal: Fix input device selection for camcorder stereo recording

- Single mic device would be seleted in camcorder, even if
  the dual mic enabled.
- In camcorder, the input device was force to select
  SND_DEVICE_IN_CAMCORDER_MIC, which is a singal mic.
- Fix by selecting dmic device as input devices in camcorder,
  Only when the fluence type is dual mic and the channel
  count is 2.

Change-Id: I4f6b7d54a3e7e6ddb98355d20c4bc28466905550
CRs-Fixed: 669982