[LITE][DOC] Add kernel profiler doc for add operation. test=develop (#3713)

* [LITE][DOC] Add kernel profiler doc for add operation. test=develop

* add argmax profiler info. test=develop

docs/develop_guides/add_operation.md

@@ -107,6 +107,13 @@
         using param_t = operators::ArgmaxParam;
         void Run() override;
         virtual ~ArgmaxCompute() = default;
+    #ifdef LITE_WITH_PROFILE
+        virtual void SetProfileRuntimeKernelInfo(
+            paddle::lite::profile::OpCharacter* ch) {
+            ch->kernel_func_name = kernel_func_name_;
+        }
+        std::string kernel_func_name_{"NotImplForArgmax"};
+    #endif
     };
     ```
 - 在paddlelite/lite/kernels/arm/目录下新建argmax_compute.cc文件，主要实现Run函数。`Run()`函数调用paddlelite/lite/bachends/arm/math/argmax.h中的`argmax_func()`函数，根据输入计算输出。最后在argmax_compute.cc文件中，我们绑定argmax的输入输出（为tensor的输入参数都需要绑定），代码如下：
@@ -117,6 +124,9 @@
         lite::Tensor* output = param.Out;
         int axis = param.Axis;
         lite::arm::math::argmax_func(input, axis, output);
+    #ifdef LITE_WITH_PROFILE
+        kernel_func_name_ = "argmax_func";
+    #endif
         return;
     }
 

lite/kernels/arm/argmax_compute.cc

@@ -35,6 +35,9 @@ void ArgmaxCompute::Run() {
   }
 
   lite::arm::math::argmax_func(input, axis, output);
+#ifdef LITE_WITH_PROFILE
+  kernel_func_name_ = "argmax_func";
+#endif
   return;
 }
 

lite/kernels/arm/argmax_compute.h

@@ -16,6 +16,10 @@
 #include <algorithm>
 #include "lite/core/kernel.h"
 #include "lite/operators/argmax_op.h"
+#ifdef LITE_WITH_PROFILE
+#include <string>
+#include "lite/core/profile/profiler.h"
+#endif
 
 namespace paddle {
 namespace lite {
@@ -29,6 +33,14 @@ class ArgmaxCompute : public KernelLite<TARGET(kARM), PRECISION(kFloat)> {
   void Run() override;
 
   virtual ~ArgmaxCompute() = default;
+
+#ifdef LITE_WITH_PROFILE
+  virtual void SetProfileRuntimeKernelInfo(
+      paddle::lite::profile::OpCharacter* ch) {
+    ch->kernel_func_name = kernel_func_name_;
+  }
+  std::string kernel_func_name_{"NotImplForArgmax"};
+#endif
 };
 
 }  // namespace arm