Simplify.

CMakeLists.txt

@@ -54,14 +54,11 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-if(AMR_WIND_ENABLE_SYCL AND AMR_WIND_ENABLE_OPENMP)
+if((AMR_WIND_ENABLE_SYCL OR AMR_WIND_ENABLE_ROCM OR AMR_WIND_ENABLE_CUDA) AND AMR_WIND_ENABLE_OPENMP)
   message(FATAL_ERROR "Using OpenMP with a GPU backend is unsupported.")
 endif()
 
 if(AMR_WIND_ENABLE_CUDA)
-  if(AMR_WIND_ENABLE_OPENMP)
-    message(FATAL_ERROR "Using OpenMP with a GPU backend is unsupported.")
-  endif()
   enable_language(CUDA)
   if(CMAKE_CUDA_COMPILER_VERSION VERSION_LESS "10.0")
     message(FATAL_ERROR "Your nvcc version is ${CMAKE_CUDA_COMPILER_VERSION} which is unsupported."
@@ -70,9 +67,6 @@ if(AMR_WIND_ENABLE_CUDA)
 endif()
 
 if(AMR_WIND_ENABLE_ROCM)
-  if(AMR_WIND_ENABLE_OPENMP)
-    message(FATAL_ERROR "Using OpenMP with a GPU backend is unsupported.")
-  endif()
   find_package(HIP REQUIRED)
   if(NOT DEFINED AMD_ARCH)
     # Set default AMD architectures (based on Frontier)