USB: gadget: f_audio_source: Switch to DMA memory to support MMAP

- Music takes more time to resume on speaker after USB unplug.
- USB driver does not support the Non-blocking mode i.e.
  MMAP mode. When the USB is unplugged, write is blocked for
  10 sec, and after a 10 sec timeout, the USB accessory device
  is closed and the device switch to speaker occurs.
- Changes were made to implement the MMAP interface in the
  driver that is Non-blocking. Hence, the write thread gets
  unblocked immediately and the switch to speaker is
  instantaneous.

CRs-Fixed: 453134
Change-Id: I3020f56db31e78aed114e6a4021f519b1ed234c3
Signed-off-by: Deepa Madiregama <dmadireg@codeaurora.org>
ASoC: apq8064 : Fix for voice over USB in Fusion target

- currently APQ assumes 8k and mono as USB parameters for
  voice over USB but MDM configures with 48k and stereo
  as USB parameters which results a mismatch between APQ
  and MDM configurations
- Set the APQ parameters in sync with MDM

Change-Id: Ibbdf6bb620b4fd2c25ba6879477488c85c5defc9
Signed-off-by: VidyaKumar Athota <vathota@codeaurora.org>
CRs-Fixed: 415079
sound: Enable the switch device for USB digital audio

 * Samsung has this commented out in favor of their proprietary dock
   solution, but we can support both.
 * Enables full support for USB DACs on Android :)

Change-Id: Id6d576886924e6c57d6e3fe920eee3ee1833ad98