V4L/DVB: gspca_tv8532: remove a whole bunch of unnecessary register writes

There is a problem with certain tv8532 cams, where sometimes there
hsync/vsync locks one pixel of where it normally locks. While trying to
fix this (which I failed to do). I noticed there are lots if duplicate
register writes and unnecessary register reads in the tv8532 driver. This
patch cleanes these ups (which has no negative effects, but unfortunately
also does not help).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>