v4l: xilinx-multi-scaler: Corrects the format struct in TRY_FMT

v4l: xilinx-multi-scaler: Corrects the format struct in TRY_FMT

V4L2 specification suggests the driver corrects the
format struct if any of the dimensions is unsupported.

The patch limits the minimum height and width to 64 and
maximum height and width to the value set in DT.

Signed-off-by: Suresh Gupta <suresh.gupta@xilinx.com>
Reviewed-by: Satish Kumar Nagireddy <satish.nagireddy.nagireddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>