Fix some define forwarding logic in codegen

Author: andy31415

build/chip/chip_codegen.gni

@@ -80,11 +80,10 @@ template("_chip_build_time_codegen") {
 
     forward_variables_from(invoker, [ "deps" ])
 
-    if (defined(deps)) {
-      deps += [ ":${_name}_codegen" ]
-    } else {
-      deps = [ ":${_name}_codegen" ]
+    if (!defined(deps)) {
+      deps = []
     }
+    deps += [ ":${_name}_codegen" ]
   }
 }
 

src/app/chip_data_model.gni

@@ -70,7 +70,11 @@ template("chip_data_model") {
 
     public_configs = [ ":${_data_model_name}_config" ]
 
-    deps = [ "${chip_root}/src/app/common:cluster-objects" ]
+    if (!defined(deps)) {
+      deps = []
+    }
+
+    deps += [ "${chip_root}/src/app/common:cluster-objects" ]
   }
 
   _use_default_im_dispatch = !defined(invoker.use_default_im_dispatch) ||
@@ -89,7 +93,10 @@ template("chip_data_model") {
       sources = []
     }
 
-    deps = [ ":${_data_model_name}_codegen" ]
+    if (!defined(deps)) {
+      deps = []
+    }
+    deps += [ ":${_data_model_name}_codegen" ]
 
     sources += [
       "${_app_root}/clusters/barrier-control-server/barrier-control-server.h",