ASoC: wm_adsp: Add controls for calibration and diagnostic FW

Exposed additional mixer controls to select calibration or diagnostic
firmware.

'Calibration' --> chip-dsp<id>-spk-cali.wmfw (.bin)
'Diagnostic'  --> chip-dsp<id>-spk-diag.wmfw (.bin)

Signed-off-by: Vlad Karpovich <Vlad.Karpovich@cirrus.com>
Signed-off-by: David Rhodes <david.rhodes@cirrus.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200619212651.2739-1-david.rhodes@cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>