V4L/DVB (13384): gspca - sonixj: Optimize code and add some comments.

- the i2c base address is now taken from the sn9c1xx register table

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>