Rename "features" to "device_has" in targets.json

"features" will make more sense in the context of the feature support
that we'll introduce later (related to #1878). Plus, "device_has" is
arguably a better description of the actual content of this key.

workspace_tools/remove-device-h.py

@@ -160,8 +160,8 @@ def add_to_targets(targets, device_file, verbose=False, remove=False) :
         attrs = list(parse_attributes(device_file))
         if attrs :
             for t in target :
-                targets[t]["features"] = sorted(list(set(targets[t].setdefault("features",[]) + attrs)))
-                if verbose : print("[VERBOSE] target {} now features {}".format(t, attrs))
+                targets[t]["device_has"] = sorted(list(set(targets[t].setdefault("device_has",[]) + attrs)))
+                if verbose : print("[VERBOSE] target {} now device_has {}".format(t, attrs))
             if remove is True:
                 remove_attributes(device_file)
 

workspace_tools/targets.py

@@ -58,7 +58,7 @@ def cached(func):
 class Target:
     # Cumulative attributes can have values appended to them, so they
     # need to be computed differently than regular attributes
-    __cumulative_attributes = ['extra_labels', 'macros', 'features']
+    __cumulative_attributes = ['extra_labels', 'macros', 'device_has']
 
     # Utility function: traverse a dictionary and change all the strings in the dictionary to
     # ASCII from Unicode. Needed because the original mbed target definitions were written in

workspace_tools/toolchains/__init__.py

@@ -298,7 +298,7 @@ class mbedToolchain:
 
             # Add target's symbols
             self.symbols += self.target.macros
-            self.symbols += ["DEVICE_" + feature + "=1" for feature in self.target.features]
+            self.symbols += ["DEVICE_" + data + "=1" for data in self.target.device_has]
             # Add extra symbols passed via 'macros' parameter
             self.symbols += self.macros