GPU CMake: Switch from deprecated AMDGPU_TARGETS to GPU_TARGETS

Author: davidrohr

dependencies/FindO2GPU.cmake

@@ -234,7 +234,7 @@ endif()
 if(ENABLE_HIP)
   if(HIP_AMDGPUTARGET)
     set(CMAKE_HIP_ARCHITECTURES "${HIP_AMDGPUTARGET}")
-    set(AMDGPU_TARGETS "${HIP_AMDGPUTARGET}")
+    set(GPU_TARGETS "${HIP_AMDGPUTARGET}")
   endif()
   if(NOT "$ENV{CMAKE_PREFIX_PATH}" MATCHES "rocm" AND NOT CMAKE_PREFIX_PATH MATCHES "rocm" AND EXISTS "/opt/rocm/lib/cmake/")
     list(APPEND CMAKE_PREFIX_PATH "/opt/rocm/lib/cmake")