ASoC: simple-card: Add missing of_node_put() in case of error

In the error path, a of_node_put() for platform is missing.
Just add it.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/20230523151223.109551-9-herve.codina@bootlin.com


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