[AIX] build fix for using system install protobuf/onnx (microsoft#22302)

### Description
Fixing merge issue occurred in
microsoft#22272

### Motivation and Context
To build onnxruntime using system installed protobuf/onnx.

cmake/onnxruntime_unittests.cmake

@@ -1669,7 +1669,7 @@ if (NOT CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
       list(APPEND onnxruntime_customopregistration_test_LIBS ${TENSORRT_LIBRARY_INFER})
     endif()
     if (${CMAKE_SYSTEM_NAME} MATCHES "AIX")
-      list(APPEND onnxruntime_customopregistration_test_LIBS onnxruntime_graph onnxruntime_session onnxruntime_providers onnxruntime_lora onnxruntime_framework onnxruntime_util onnxruntime_mlas onnxruntime_optimizer onnxruntime_flatbuffers iconv re2 libprotobuf-lite onnx_proto nsync_cpp)
+      list(APPEND onnxruntime_customopregistration_test_LIBS onnxruntime_graph onnxruntime_session onnxruntime_providers onnxruntime_lora onnxruntime_framework onnxruntime_util onnxruntime_mlas onnxruntime_optimizer onnxruntime_flatbuffers iconv re2 ${PROTOBUF_LIB} onnx onnx_proto nsync_cpp)
     endif()
     AddTest(DYN
             TARGET onnxruntime_customopregistration_test
@@ -1788,7 +1788,7 @@ if (onnxruntime_BUILD_SHARED_LIB AND NOT CMAKE_SYSTEM_NAME STREQUAL "Emscripten"
 
   set(onnxruntime_logging_apis_test_LIBS onnxruntime_common onnxruntime_test_utils)
   if (${CMAKE_SYSTEM_NAME} MATCHES "AIX")
-    list(APPEND onnxruntime_logging_apis_test_LIBS onnxruntime_session onnxruntime_util onnxruntime_lora onnxruntime_framework onnxruntime_common onnxruntime_graph  onnxruntime_providers onnxruntime_mlas onnxruntime_optimizer onnxruntime_flatbuffers iconv re2 libprotobuf-lite ${PROTOBUF_LIB} onnx onnx_proto nsync_cpp)
+    list(APPEND onnxruntime_logging_apis_test_LIBS onnxruntime_session onnxruntime_util onnxruntime_lora onnxruntime_framework onnxruntime_common onnxruntime_graph  onnxruntime_providers onnxruntime_mlas onnxruntime_optimizer onnxruntime_flatbuffers iconv re2 ${PROTOBUF_LIB} onnx onnx_proto nsync_cpp)
      endif()
 
   if(NOT WIN32)