v4l: xilinx: sdirxss: Detect mode based on capability

v4l: xilinx: sdirxss: Detect mode based on capability

Set the mode detection based on IP configuration.
If the IP is configured for 3G mode then don't allow detection for
6G and 12G Integral/Fractional modes.
If the IP is configured for 6G mode then don't allow detection for 12G
Integral/Fractional modes.

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