conf: USB-Audio: Add more Scarlett devices to the IEC958 blacklist

The Scarlett Solo and 2i2 don't have S/PDIF outputs.

Link: https://lore.kernel.org/alsa-devel/ZeWGbxZIc7AF96h0@m.b4.vu/
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

src/conf/cards/USB-Audio.conf

@@ -66,8 +66,11 @@ USB-Audio.pcm.iec958_device {
 	"Plantronics USB Headset" 999
 	"Plantronics Wireless Audio" 999
 	"SB WoW Headset" 999
+	"Scarlett 2i2 4th Gen" 999
 	"Scarlett 2i2 USB" 999
 	"Scarlett 2i4 USB" 999
+	"Scarlett Solo 4th Gen" 999
+	"Scarlett Solo USB" 999
 	"Sennheiser USB headset" 999
 	"SWTOR Gaming Headset by Razer" 999
 	"ThinkStation P620 Main" 999