change to new spelling of the -gpu switch for nvc++

Author: ericniebler

CMakeLists.txt

@@ -282,7 +282,7 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "NVHPC")
     # Unset these if using nvc++
     disable_compiler(LANG CUDA)
 
-    set(_nvhpc_seperate_memory_flags "-gpu=nomanaged")
+    set(_nvhpc_seperate_memory_flags "-gpu=mem:separate")
     # if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 24.5.0)
     #     set(_nvhpc_seperate_memory_flags "-gpu=mem:separate")
     # endif()