[media] af9013: add debug for IF frequency

Used IF frequency is one of the most important parameter to know.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb-frontends/af9013.c

@@ -606,6 +606,8 @@ static int af9013_set_frontend(struct dvb_frontend *fe)
 		else
 			if_frequency = state->config.if_frequency;
 
+		dbg("%s: if_frequency=%d", __func__, if_frequency);
+
 		sampling_freq = if_frequency;
 
 		while (sampling_freq > (state->config.clock / 2))