Add the digital-mic support with ALC262 auto model.
The new ALC262 models have the digital mic at NID 0x12.  This widget
isn't checked in the current alc262_auto_create_analog_input_ctls()
since it's under 0x18.  So, just reuse the routine for alc269 to fix
the behavior.

But, it doesn't suffice: the digital mic is supported only with the
ADC0, we have to exclude other ADCs when d-mic is detected.
Signed-off-by: Takashi Iwai <tiwai@suse.de>