[media] media: imx: csi: add frame size/interval enumeration

Add frame size and frame interval enumeration to CSI.

CSI can downscale the image independently horizontally and vertically by a
factor of two, which enumerates to four different frame sizes at the
output pads. The input pad supports a range of frame sizes.

CSI can also drop frames, resulting in frame rate reduction, so
enumerate the resulting possible output frame rates.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>