ALSA: usb-audio: Add implicit feedback quirk for MODX

This patch fixes audio distortion on playback for the Yamaha MODX.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Tested-by: Frank Slotta <frank.slotta@posteo.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201104120705.GA19126@b4.vuSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/pcm.c

@@ -345,6 +345,7 @@ static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
 		ifnum = 2;
 		goto add_sync_ep_from_ifnum;
 	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
+	case USB_ID(0x0499, 0x172a): /* Yamaha MODX */
 		ep = 0x86;
 		ifnum = 2;
 		goto add_sync_ep_from_ifnum;