V4L/DVB: gspca - sn9c20x: Add upside down detection

Add support for detecting webcams that are mounted
upside down in laptops. Currently the only two known
are two MSI modesl using the 0c45:624f.

Signed-off-by: Brian Johnson <brijohn@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>