ALSA: scarlett2: Add support for Air Presence + Drive option

Extend the existing "air" option support from Scarlett Gen 3, which
had two states (off/on), to accommodate Scarlett Gen 4's new state:
Presence + Drive.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/a9ccda7222842a72e4ce7aa258614ff45248bb16.1703612638.git.g@b4.vu