ASoC: wm_adsp: create ALSA controls from wm_adsp driver

Now that we have a codec_probe stage initialization in the wm_adsp
driver, we can make the wm_adsp driver create its own ALSA controls
instead of having that responsibility pushed to every codec driver.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>