soundwire: intel: remove stream handling from .prepare and .hw_free

soundwire: intel: remove stream handling from .prepare and .hw_free

Now that the stream is handled at the dai-link level (in the machine
driver), we can remove the stream handling at the dai level. We still
need these callbacks to perform dai-level resource handling
(i.e. addition/removal of a master).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903204739.31206-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>