ALSA: scarlett2: Fix Scarlett 4th Gen autogain status values

The meanings of the raw_auto_gain_status values were originally
guessed through experimentation, but the official names have now been
discovered. Update the autogain status control strings accordingly.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Fixes: 0a995e38 ("ALSA: scarlett2: Add support for software-controllable input gain")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-ID: <8bd12a5e7dc714801dd9887c4bc5cb35c384e27c.1710047969.git.g@b4.vu>