added empty out (#4757)

Summary:
Pull Request resolved: #4757

~

Differential Revision: D61407442

Author: zonglinpeng

backends/cadence/aot/functions.yaml

@@ -57,10 +57,10 @@
     - arg_meta: null
       kernel_name: torch::executor::embedding_out
 
-- op: expand_copy.out
+- op: empty.out
   kernels:
     - arg_meta: null
-      kernel_name: torch::executor::expand_copy_out
+      kernel_name: torch::executor::empty_out
 
 - op: full.out
   kernels:

backends/cadence/reference/operators/CMakeLists.txt

@@ -48,8 +48,7 @@ set(_aten_ops__srcs
     "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_sub.cpp"
     "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_to_copy.cpp"
     "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_where.cpp"
-    "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_expand_copy.cpp"
-    "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_gelu.cpp")
+    "${EXECUTORCH_ROOT}/kernels/portable/cpu/op_empty.cpp")
 add_library(aten_ops_cadence ${_aten_ops__srcs})
 target_link_libraries(aten_ops_cadence PUBLIC executorch)
 target_link_libraries(aten_ops_cadence PRIVATE cadence_kernels)