ALSA: usb: mixer: volume quirk for CM102-A+/102S+

Currently it's not possible to set volume lower than 26% (it just mutes).

Also fixes this warning:

  Warning! Unlikely big volume range (=9472), cval->res is probably wrong.
  [13] FU [PCM Playback Volume] ch = 2, val = -9473/-1/1

, and volume works fine for full range.

Signed-off-by: Federico Cuello <fedux@fedux.com.ar>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/mixer.c

@@ -967,6 +967,14 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
 		}
 		break;
 
+	case USB_ID(0x0d8c, 0x0103):
+		if (!strcmp(kctl->id.name, "PCM Playback Volume")) {
+			usb_audio_info(chip,
+				 "set volume quirk for CM102-A+/102S+\n");
+			cval->min = -256;
+		}
+		break;
+
 	case USB_ID(0x0471, 0x0101):
 	case USB_ID(0x0471, 0x0104):
 	case USB_ID(0x0471, 0x0105):