V4L/DVB (8957): zr36067: Restore the default pixel format

Restore the default pixel format to YUYV as it used to be before
kernel 2.6.23. It was accidentally changed to BGR3 by commit
603d6f2c.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>