Make hsa_agent_t handles use pointer to device::Device

For roc devices create hsa_agent_t handles using a pointer to the
device::Device. This ensures each device has a different hsa_agent_t
handle. This may be necessary to ensure the loader symbol lookup will
search only symbols for the correct device.

Change-Id: Iee6dd40d68bf22a02ce8c75cbe5ac8f5a0d9e418

rocclr/device/gpu/gpuprogram.cpp

@@ -1619,8 +1619,7 @@ bool HSAILProgram::linkImpl(amd::option::Options* options) {
     }
   }
   // ACL_TYPE_CG stage is not performed for offline compilation
-  hsa_agent_t agent;
-  agent.handle = 1;
+  hsa_agent_t agent = {amd::Device::toHandle(&(device()))};
   if (hsaLoad) {
     executable_ = loader_->CreateExecutable(HSA_PROFILE_FULL, NULL);
     if (executable_ == NULL) {