V4L/DVB (11213): gspca - sq905c: New subdriver.

The code in the new sq905c.c is based upon the structure of the code in
gspca/sq905.c, and upon the code in libgphoto2/camlibs/digigr8, which supports
the same set of cameras in stillcam mode. I am a co-author of gspca/sq905.c and
I am the sole author of libgphoto2/camlibs/digigr8, which is licensed under the
LGPL. I hereby give myself permission to use my own code from libgphoto2 in
gspca/sq905c.c.

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