V4L/DVB (9072): S2API: Add DTV_API_VERSION command

This allows application developers to query the dvb-core API version
dynamically, helping developers understand whether certain features
will be available.

Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h
index b561626..eb98f8c 100644
--- a/include/linux/dvb/frontend.h
+++ b/include/linux/dvb/frontend.h
@@ -268,6 +268,7 @@
 #define DTV_FE_CAPABILITY	16
 #define DTV_DELIVERY_SYSTEM	17
 
+#define DTV_API_VERSION				35
 
 typedef enum fe_pilot {
 	PILOT_ON,