soundwire: intel: add comment for control stream cap/chmap

add comment and newline to mark out control stream capabilities and
chmap. These registers are unused by the driver, only dumped in
debugfs.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220823053846.2684635-7-yung-chuan.liao@linux.intel.com


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