ASoC: WM8994: Ensure late enable events are processed for the ADCs

Ensure that the ADCs are provided with a clock as the previous patch
"ASoC: WM8994: Improve playback robustness" did not handle this case
properly.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org