ALSA: us122l: enable compile testing

This USB driver currently depends on X86 for some undocumented reason.
Since it compiles just fine for arm, we can at least enable compile
testing.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/Kconfig

@@ -91,7 +91,7 @@ config SND_USB_CAIAQ_INPUT
 
 config SND_USB_US122L
 	tristate "Tascam US-122L USB driver"
-	depends on X86
+	depends on X86 || COMPILE_TEST
 	select SND_HWDEP
 	select SND_RAWMIDI
 	help