ASoC: mediatek: mt8173: fix device_node leak

[ Upstream commit 49343378

 ]

Fixes the device_node leak.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20211224064719.2031210-2-tzungbi@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>