[media] cxusb: Prepare for si2157 driver getting more parameters

Modify all users of si2157_config to correctly initialize all not
listed values to 0.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/usb/dvb-usb/cxusb.c

@@ -1386,6 +1386,7 @@ static int cxusb_tt_ct2_4400_attach(struct dvb_usb_adapter *adap)
 	st->i2c_client_demod = client_demod;
 
 	/* attach tuner */
+	memset(&si2157_config, 0, sizeof(si2157_config));
 	si2157_config.fe = adap->fe_adap[0].fe;
 	memset(&info, 0, sizeof(struct i2c_board_info));
 	strlcpy(info.type, "si2157", I2C_NAME_SIZE);