ucm2: sof-hda-dsp: DMICS may not be present

[GitHub issues - opened]

alsa-project/alsa-ucm-conf issue #80 was opened from plbossart:

UCM files assume that when SOF is used, the number of DMICs is between 1 and 4.

That's an invalid assumption in the following two cases:
a) the user plays with kernel parameters to select SOF on a platform without DMIC
options snd_intel_dspcfg dsp_driver=3
b) the user plays with kernel parameters to work-around invalid dmic information, e.g. for UpExtreme the NHLT information reports 4 microphones but none are attached to the connector by default
options snd_sof_intel_hda_common dmic_num=0

In those two cases, the only solution is to comment out the entire 'Mic1' section in ucm2/sof-hda-dsp/HiFi.conf. It'd be nicer to detect this case with the component information

The machine driver currently only provides the cfg-dmics component string when the real or overridden number of dmics is > 0.
The component string is as follows

````
amixer -Dhw:0 info
Card hw:0 'sofhdadsp'/'AAEON-UP_WHL01-V1.0'
  Mixer name	: 'Realtek ALC892'
  Components	: 'HDA:8086280b,80860101,00100000 HDA:10ec0892,160d0892,00100302'
  Controls      : 40
  Simple ctrls  : 15
````
Reported by @worldgeek and confirmed on my platform.

@perexg @kv2019i @libinyang FYI

Issue URL     : https://github.com/alsa-project/alsa-ucm-conf/issues/80
Repository URL: https://github.com/alsa-project/alsa-ucm-conf