[media] gspca - ov519: Change the ovfx2 bulk transfer size

The 'normal' bulk transfer size did not work for 800x600.
By git commit c42cedbb

, this 'normal' size was used for 1600x1200 only.
It will now be used back again for all resolutions but 800x600.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>