[media] dvb-usb-dvbsky: fix i2c adapter for sp2 device

It is wrong that sp2 device uses the i2c adapter from m88ds3103 return.
sp2 device sits on the same i2c bus with m88ds3103, not behind m88ds3103.

Signed-off-by: Nibble Max <nibble.max@gmail.com>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>