ASoC: rt711-sdw: use cancel_work_sync() for .remove

ASoC: rt711-sdw: use cancel_work_sync() for .remove

Make sure the workqueues are not running after the .remove() callback,
which can lead to timeout errors.

A previous fix to use cancel_work_sync was applied for the suspend
case but the remove case is missing

Fixes: 66628856499a ('ASoC: rt711: wait for the delayed work to finish when the system suspends')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Link: https://lore.kernel.org/r/20210204201739.25206-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>