add erf kernel

mindspore/lite/nnacl/fp32/arithmetic_self_fp32.c

@@ -138,3 +138,10 @@ int ElementReciprocal(const float *input, float *output, const int element_size)
   }
   return NNACL_OK;
 }
+
+int ElementErf(const float *input, float *output, const int element_size) {
+  for (int i = 0; i < element_size; i++) {
+    output[i] = erff(input[i]);
+  }
+  return NNACL_OK;
+}

mindspore/lite/nnacl/fp32/arithmetic_self_fp32.h

@@ -53,6 +53,8 @@ int ElementCeil(const float *input, float *output, const int number);
 int ElementNegative(const float *input, float *output, const int element_size);
 
 int ElementReciprocal(const float *input, float *output, const int element_size);
+
+int ElementErf(const float *input, float *output, const int element_size);
 #ifdef __cplusplus
 }
 #endif

mindspore/lite/src/runtime/kernel/arm/fp32/arithmetic_self_fp32.cc

@@ -42,7 +42,8 @@ ArithmeticSelfFunc ArithmeticSelfCPUKernel::GetArithmeticSelfFun(int primitive_t
                                       {mindspore::schema::PrimitiveType_Ceil, ElementCeil},
                                       {mindspore::schema::PrimitiveType_Round, ElementRound},
                                       {mindspore::schema::PrimitiveType_Neg, ElementNegative},
-                                      {mindspore::schema::PrimitiveType_Reciprocal, ElementReciprocal}};
+                                      {mindspore::schema::PrimitiveType_Reciprocal, ElementReciprocal},
+                                      {mindspore::schema::PrimitiveType_Erf, ElementErf}};
   for (size_t i = 0; i < sizeof(type_func_table) / sizeof(TYPE_FUNC_INFO); i++) {
     if (type_func_table[i].primitive_type_ == primitive_type) {
       return type_func_table[i].func_;

mindspore/lite/src/runtime/kernel/arm/fp32/arithmetic_self_fp32.h

@@ -22,6 +22,7 @@
 using mindspore::schema::PrimitiveType_Abs;
 using mindspore::schema::PrimitiveType_Ceil;
 using mindspore::schema::PrimitiveType_Cos;
+using mindspore::schema::PrimitiveType_Erf;
 using mindspore::schema::PrimitiveType_Floor;
 using mindspore::schema::PrimitiveType_Log;
 using mindspore::schema::PrimitiveType_LogicalNot;