[media] media: fix radio-sf16fmr2 build when SND is not enabled

When CONFIG_SND is not enabled, radio-sf16fmr2 build fails with:

so make this driver depend on SND.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/Kconfig

@@ -201,7 +201,7 @@ config RADIO_SF16FMI
 
 config RADIO_SF16FMR2
 	tristate "SF16FMR2 Radio"
-	depends on ISA && VIDEO_V4L2
+	depends on ISA && VIDEO_V4L2 && SND
 	---help---
 	  Choose Y here if you have one of these FM radio cards.