Skip the test on non-x86_64 platforms as xattention is supported only on Intel CPUs.

Author: mangguo321

src/plugins/intel_cpu/tests/unit/CMakeLists.txt

@@ -32,7 +32,8 @@ if(NOT X86_64)
       ${CMAKE_CURRENT_SOURCE_DIR}/snippets_transformations/x64
       ${CMAKE_CURRENT_SOURCE_DIR}/nodes/eltwise_node_test.cpp
       ${CMAKE_CURRENT_SOURCE_DIR}/brgemm_executor_test.cpp
-      ${CMAKE_CURRENT_SOURCE_DIR}/xattention_test.cpp)
+      ${CMAKE_CURRENT_SOURCE_DIR}/xattention_test.cpp
+      ${CMAKE_CURRENT_SOURCE_DIR}/softmax_kernel_test.cpp)
 endif()
 
 if (NOT ENABLE_MLAS_FOR_CPU)