[media] V4L: mx2-camera: avoid overflowing 32-bits

In mx2_camera_try_fmt(), when applying i.MX25 restrictions to frame sizes,
the height is checked to be <= 0xffff. But later an integer multiplication
height * 4 * 0x3ffff is performed, which will overflow even for bounded
height values. This patch switches to using 64-bit multiplication and
division to avoid overflowing.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>