[media] dvb-core: add support for a DVBv5 get_frontend() callback

Creates a DVBv5 get_frontend call, renaming the DVBv3 one to
get_frontend_legacy(), while not all frontends are converted.

After the conversion for all drivers, get_frontend_legacy()
will be removed.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/frontends/dib9000.c b/drivers/media/dvb/frontends/dib9000.c
index c7b4910..4d82a4a 100644
--- a/drivers/media/dvb/frontends/dib9000.c
+++ b/drivers/media/dvb/frontends/dib9000.c
@@ -1883,7 +1883,7 @@
 			dprintk("TPS lock on the slave%i", index_frontend);
 
 			/* synchronize the cache with the other frontends */
-			state->fe[index_frontend]->ops.get_frontend(state->fe[index_frontend], fep);
+			state->fe[index_frontend]->ops.get_frontend_legacy(state->fe[index_frontend], fep);
 			for (sub_index_frontend = 0; (sub_index_frontend < MAX_NUMBER_OF_FRONTENDS) && (state->fe[sub_index_frontend] != NULL);
 			     sub_index_frontend++) {
 				if (sub_index_frontend != index_frontend) {
@@ -2515,7 +2515,7 @@
 
 	.set_frontend_legacy = dib9000_set_frontend,
 	.get_tune_settings = dib9000_fe_get_tune_settings,
-	.get_frontend = dib9000_get_frontend,
+	.get_frontend_legacy = dib9000_get_frontend,
 
 	.read_status = dib9000_read_status,
 	.read_ber = dib9000_read_ber,