upgrade FindCUDNN module to better deal with dlls and targets

cmake/Modules/FindCUDNN.cmake

@@ -70,10 +70,11 @@ mark_as_advanced(CUDNN_LIBRARY CUDNN_INCLUDE_DIR)
 #    Release libraries), we will set appropriate target properties for these.
 # 2. However, for most systems, we will only register the import location and
 #    include directory.
-
-# Look for dlls, for Release and Debug libraries.
 if(WIN32)
-  string( REPLACE ".lib" ".dll" CUDNN_LIBRARY_DLL "${CUDNN_LIBRARY}" )
+  set(CUDNN_DLL_DIR ${CUDNN_INCLUDE_DIR})
+  list(TRANSFORM CUDNN_DLL_DIR APPEND "/../bin")
+  message(STATUS "CUDNN_DLL_DIR: ${CUDNN_DLL_DIR}")
+  find_file(CUDNN_LIBRARY_DLL NAMES cudnn64_7.dll PATHS ${CUDNN_DLL_DIR})
 endif()
 
 if( CUDNN_FOUND AND NOT TARGET CuDNN::CuDNN )