cmake: remove duplicated spdk linkage

Signed-off-by: Kefu Chai <kchai@redhat.com>

src/os/CMakeLists.txt

@@ -90,15 +90,9 @@ if(HAVE_LIBZFS)
 endif()
 
 if(WITH_SPDK)
-  # librt is used by libspdk_env_dpdk
   target_link_libraries(os
-    ${SPDK_LIBRARIES} rt
-    ${DPDK_LIBRARIES})
-  target_include_directories(os
-    SYSTEM
-    PRIVATE
-    ${DPDK_INCLUDE_DIR})
-endif(WITH_SPDK)
+    ${SPDK_LIBRARIES})
+endif()
 
 if(WITH_LTTNG)
   add_dependencies(os objectstore-tp)
@@ -119,14 +113,6 @@ if(WITH_BLUESTORE)
     DESTINATION bin)
 endif()
 
-if(WITH_SPDK)
-  include(BuildSPDK)
-  include_directories(SYSTEM ${SPDK_INCLUDE_DIR})
-  foreach(lib nvme log env_dpdk util)
-    target_link_libraries(os spdk_${lib})
-  endforeach()
-endif(WITH_SPDK)
-
 if(WITH_PMEM)
   include(ExternalProject)
   ExternalProject_Add(nvml_ext