ASoC: codecs: wm0010: use DECLARE_COMPLETION_ONSTACK() macro

Follow recommendation in Documentation/scheduler/completion.rst and
use macro to declare local 'struct completion'

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200813175442.59067-1-pierre-louis.bossart@linux.intel.com


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