BaseTools: Fixed a incremental build bug

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2451

If removing a header file from source code and file
system, the incremental build will fail.

This patch is to fix this issue by setting each header file
as a target without any actions in makefile.

Signed-off-by: Bob Feng <bob.c.feng@intel.com>

Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

BaseTools/Source/Python/AutoGen/IncludesAutoGen.py

@@ -1,7 +1,7 @@
 ## @file
 # Build cache intermediate result and state
 #
-# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2019 - 2020, Intel Corporation. All rights reserved.<BR>
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 from Common.caching import cached_property
@@ -65,6 +65,9 @@ class IncludesAutoGen():
             print(e)
         SaveFileOnChange(os.path.join(self.makefile_folder,"dependency"),deps_include_str,False)
 
+    def CreateDepsTarget(self):
+        SaveFileOnChange(os.path.join(self.makefile_folder,"deps_target"),"\n".join([item +":" for item in self.DepsCollection]),False)
+
     @cached_property
     def deps_files(self):
         """ Get all .deps file under module build folder. """