ASoC: SDCA: add route by the number of input pins in MU entity

This patch removed the code where num_sources should be the same as cn_list.
For better resilience, it would be preferable to explicitly add the route
mapping the input pins to this MU entity.

Signed-off-by: Shuming Fan <shumingf@realtek.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20250721112346.388542-1-shumingf@realtek.com


Signed-off-by: Mark Brown <broonie@kernel.org>