[media] ov2640: fix duplicate width+height returning from ov2640_select_win()

ov2640_select_win() returns height and width values as part of struct
ov2640_win_size, so there is no point in modifying the passed height and
width parameters, too.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>