V4L/DVB (10931): zoran: Drop the lock_norm module parameter

The lock_norm module parameter doesn't look terribly useful. If you
don't want to change the norm, just don't change it. As a matter of
fact, no other v4l driver has such a parameter.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>