soundwire: intel: add link_list to handle interrupts with a single thread

In MSI mode, the use of separate handlers and threads for the Intel
IPC, stream and SoundWire shared interrupt leads to timeouts and lost
interrupts.

The solution is to merge all interrupt handling across all links with
a single thread function. The use of a linked list enables this thread
function to walk through all contexts and figure out which link needs
attention.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191212014507.28050-9-pierre-louis.bossart@linux.intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>