ASoC: wm_adsp: Expose the DSP boot work actions as wm_adsp_power_up()

To support self-booting DSPs that are considered always running, the work
that is usually invoked as part of a DAPM sequence needs to be triggered
by a client of wm_adsp as part of it's startup sequence.

These actions load firmware files that might create ALSA controls and
apply configuration to the device.

Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230320112245.115720-6-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>