Added --clang flag to tnl-cuda-arch

#include <stdio.h> 

#include <string.h>

int main() {

int main( int argc, char** argv )

{

    int num_devices = 0;

    cudaError_t error_id = cudaGetDeviceCount( &num_devices );

            if( i > 0 )

                printf(" ");

            if( argc == 2 && strcmp( argv[1], "--clang" ) == 0 ) {

                printf( "--cuda-gpu-arch=sm_%d%d",

                        prop.major, prop.minor );

            }

            else {

                printf( "-gencode arch=compute_%d%d,code=sm_%d%d",

                        prop.major, compute_minor, prop.major, prop.minor );

            }

    }

    printf("\n");

}