remove redundant option

Author: rongou

CMakeLists.txt

@@ -171,13 +171,6 @@ if(USE_NVTX)
     set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --define-macro USE_NVTX")
 endif(USE_NVTX)
 
-option(PER_THREAD_DEFAULT_STREAM "Build with per-thread default stream" OFF)
-if(PER_THREAD_DEFAULT_STREAM)
-    message(STATUS "Using per-thread default stream")
-    add_compile_definitions(CUDA_API_PER_THREAD_DEFAULT_STREAM)
-    set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --default-stream per-thread")
-endif(PER_THREAD_DEFAULT_STREAM)
-
 ###################################################################################################
 # - link libraries --------------------------------------------------------------------------------