ASoC: Don't oops in soc_probe_aux_dev in case of missing codec

Blind copy of codec finding algorithm from soc_bind_dai_link does not work
in soc_probe_aux_dev if matching codec name is not found. In that case the
code falls through and tries to start the probing procedure with invalid
codec pointer.

Fix this and add an error print showing the codec name that cannot be found.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>