[media] radio-sf16fmi: declare pnp_attached as static

drivers/media/radio/radio-sf16fmi.c:59:6: warning: symbol 'pnp_attached' was not declared. Should it be static?

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/radio/radio-sf16fmi.c b/drivers/media/radio/radio-sf16fmi.c
index bcd0946..28a8946 100644
--- a/drivers/media/radio/radio-sf16fmi.c
+++ b/drivers/media/radio/radio-sf16fmi.c
@@ -56,7 +56,7 @@
 
 static struct fmi fmi_card;
 static struct pnp_dev *dev;
-bool pnp_attached;
+static bool pnp_attached;
 
 #define RSF16_MINFREQ (87U * 16000)
 #define RSF16_MAXFREQ (108U * 16000)