BCM2835-V4L2: Increase minimum resolution to 32x32

https://github.com/raspberrypi/linux/issues/1498 showed
up that 16x16 is failing to work on the GPU for some reason.

GPU bug being tracked on
https://github.com/raspberrypi/firmware/issues/607


Workaround here by increasing minimum resolution via V4L2
to 32x32.

Signed-off-by: Dave Stevenson <6by9@users.noreply.github.com>