V4L/DVB (9185): S2API: Ensure we have a reasonable ROLLOFF default

Non-initialised cache values get a reasonble default.
Signed-off-by: NDarron Broad <darron@kewl.org>
Signed-off-by: NSteven Toth <stoth@linuxtv.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

include/linux/dvb/frontend.h

@@ -284,9 +284,9 @@ typedef enum fe_pilot {
 } fe_pilot_t;
 
 typedef enum fe_rolloff {
+	ROLLOFF_35, /* Implied value in DVB-S, default for DVB-S2 */
 	ROLLOFF_20,
 	ROLLOFF_25,
-	ROLLOFF_35,
 	ROLLOFF_AUTO,
 } fe_rolloff_t;