Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent codec node was also prematurely freed.

Fixes: 4d50934a ("ASoC: da7218: Add da7218 codec driver")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Acked-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable <stable@vger.kernel.org>