drivers/bus/soundwire: Add the Soundwire bus driver

This patch adds the Soundwire bus driver which,
* Resets the HDA and DSP.
* Initializes the Soundwire link which involves the link
  power-on and soudnwire master configuration.
* Enumerate the codecs, get identification information of
  connected codec and reads the codec status.
* Sends Tx message through the Sndw interface and recieves
  the corresponding ACK message.

BUG=b:151514169
BRANCH=none
TEST=Build and test boot beep on volteer.

Signed-off-by: V Sowmya <v.sowmya@intel.com>
Change-Id: I0d62333f5f103bb5bc677bb05f6d91583f22f6ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/2305490
Reviewed-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Commit-Queue: Tim Wawrzynczak <twawrzynczak@chromium.org>
8 files changed