V4L/DVB (11535): gspca - m5602-po1030: Add experimental QVGA support

Adds experimental support for QVGA. This is code is compile tested only.

Signed-off-by: Erik Andr?n <erik.andren@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>