OClCollMeshEngn: use the central ComputeMgr APIs

We no longer create our own context and get our own OpenCL device
in OClCollMeshEngn::setup. We now request a device from the central
ComputeManager.

smocore/CMakeLists.txt

@@ -60,6 +60,7 @@ target_link_libraries(smocore PRIVATE
 	Boost::system
 	Boost::log
 	${OPENCL_LIBRARIES}
+	attachmentSupport
 )
 target_link_directories(smocore PRIVATE
 	${OPENCL_LIBRARY_DIRS}