Some feature is only available when the hardware meet minimum
requirement
e.g. independent headphone require at least two DAC
Why it's a regression?
Those hda codecs with a single DAC (e.g. stac920x, alc260) and ad1986a does no support independent headphone
Also those alc66x datasheet does not mention the support of multi-streaming playback
Don't create the control when there is internal speaker
When driver assign two DAC to internal speaker and subwoofer (vt1802 on Asus g75) and it is confusing when there is no headphone playback volume control
Don't create the control when there is no headphone Jack when the user is retasked the headphone Jack to Mic by early patching
Automatically disable for those headphone mic jack when the HP Jack is retasked as mic