[media] v4l: ti-vpe: Allow usage of smaller images
The minimum width and height for VPE input/output was kept as 128 pixels. VPE
doesn't have a constraint on the image height, it requires the image width to
be at least 16 bytes.
Change the minimum supported dimensions to 32x32. This allows us to de-interlace
qcif content. A smaller image size than 32x32 didn't make much sense, so stopped
at this.