[media] dvb-usb-dvbsky: add T680CI dvb-t2/t/c usb ci box support

DVBSky T680CI dvb-t2/t/c usb ci box:
1>dvb frontend: SI2158A20(tuner), SI2168A30(demod)
2>usb controller: CY7C86013A
3>ci controller: CIMAX SP2 or its clone.

Signed-off-by: Nibble Max <nibble.max@gmail.com>
Reviewed-by: Olli Salonen <olli.salonen@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>