[media] em28xx-dvb: 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: NMatthias Schwarzott <zzam@gentoo.org>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/usb/em28xx/em28xx-dvb.c

@@ -1545,6 +1545,7 @@ static int em28xx_dvb_init(struct em28xx *dev)
 			dvb->i2c_client_demod = client;
 
 			/* attach tuner */
+			memset(&si2157_config, 0, sizeof(si2157_config));
 			si2157_config.fe = dvb->fe[0];
 			memset(&info, 0, sizeof(struct i2c_board_info));
 			strlcpy(info.type, "si2157", I2C_NAME_SIZE);