FindCUDAToolkit: Understand NVHPC versioned math library layout

The NVHPC packages bundle the CUDA math libraries in a sibling
directory (`math_libs`) instead of in with the rest of the
cuda libraries.

Depending on the NVHPC package the math_libs folder can have
versioned subdirectories, therefore we prefer finding the
same versions as the CUDA Toolkit and falling back to the
latest when not possible.

Modules/FindCUDAToolkit.cmake

@@ -844,6 +844,9 @@ if(CUDAToolkit_FOUND)
       HINTS ${CUDAToolkit_LIBRARY_DIR}
             ENV CUDA_PATH
       PATH_SUFFIXES lib64/stubs lib/x64/stubs lib/stubs stubs
+                    # Support NVHPC splayed math library layout
+                    ../../math_libs/${CUDAToolkit_VERSION_MAJOR}.${CUDAToolkit_VERSION_MINOR}/lib64
+                    ../../math_libs/lib64
     )
 
     mark_as_advanced(CUDA_${lib_name}_LIBRARY)