[build tools] Added test for configurations set from same level as feature

Author: geky

tools/test/config_test/test26/FEATURE_IPV4/lib1/mbed_lib.json

@@ -0,0 +1,8 @@
+{
+    "name": "lib1",
+    "target_overrides": {
+        "*": {
+            "features_add": ["IPV6"]
+        }
+    }
+}

tools/test/config_test/test26/FEATURE_IPV6/lib2/mbed_lib.json

@@ -0,0 +1,8 @@
+{
+    "name": "lib2",
+    "config": {
+        "test": {
+            "value": "BAD"
+        }
+    }
+}

tools/test/config_test/test26/mbed_app.json

@@ -0,0 +1,8 @@
+{
+    "target_overrides": {
+        "*": {
+            "features_add": ["IPV4"],
+            "lib2.test": "GOOD"
+        }
+    }
+}

tools/test/config_test/test26/test_data.py

@@ -0,0 +1,8 @@
+# Testing if config settings work in recursive features
+
+expected_results = {
+    "K64F": {
+        "desc": "test recursive feature configurations",
+        "lib2.test": "GOOD"
+    }
+}