[media] dvb: the core logic to handle the DVBv5 QoS properties

Add the logic to poll, reset counters and report the QoS stats
to the end user.
The idea is that the core will periodically poll the frontend for
the stats. The frontend may return -EBUSY, if the previous collect
didn't finish, or it may fill the cached data.
The value returned to the end user is always the cached data.

Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h
index 97112cd..b34922a 100644
--- a/drivers/media/dvb-core/dvb_frontend.h
+++ b/drivers/media/dvb-core/dvb_frontend.h
@@ -393,6 +393,16 @@
 	u8			atscmh_sccc_code_mode_d;
 
 	u32			lna;
+
+	/* statistics data */
+	struct dtv_fe_stats	strength;
+	struct dtv_fe_stats	cnr;
+	struct dtv_fe_stats	pre_bit_error;
+	struct dtv_fe_stats	pre_bit_count;
+	struct dtv_fe_stats	post_bit_error;
+	struct dtv_fe_stats	post_bit_count;
+	struct dtv_fe_stats	block_error;
+	struct dtv_fe_stats	block_count;
 };
 
 struct dvb_frontend {