v4l: xilinx-vpss-scaler: Add check for max width and height

v4l: xilinx-vpss-scaler: Add check for max width and height

Patch adds support to get maximum width and height from dt property.
If the parameters are not present then the IP sets the max size of
8192x4320. It then uses this value to clamp width and height instead of
fixed default value while setting format.

It also corrects the minimum width and height parameters.

Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>