V4L/DVB (13900): gspca - sunplus: Fix bridge exchanges.

A previous code optimization inverted bridge registers and values,
doing a regression in kernel  2.6.32.

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