[media] staging: as102: Add support for Sky Italia Digital Key based on the same chip

Add support for the Sky Italia Digital Key, an USB dongle offered
by Sky Italia to its customers for use with their satellite set-top-boxes.
This is the "green led" model based on the Abilis as102 chip, while the
so called "blue led" model is based on the Avermedia A867 design.

Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com>
Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>