ASoC: wm_adsp: Acknowledge controls should also check the DSP is running

We should not be writing acknowledge controls until the firmware is
running, as in the case of preloaded firmwares the DSP memory may be
unaccessible to whilst in the preloaded state. This means a write to the
control during this time could be lost.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>