ASoC: imx-card: Use helper function for_each_child_of_node_scoped()

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
Link: https://patch.msgid.link/20250603055109.3154061-5-aichao@kylinos.cn


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