dtoc: Process nodes to set up required properties

Add logic to assign property values to nodes as required by dtoc. The
references allow nodes to refer to each other in C code. The macros used
by dtoc are not yet defined in driver model. They will be added along
with the actual driver model implementation.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/dtoc/src_scan.py

@@ -188,6 +188,17 @@ class Scanner:
         self._uclass = {}
         self._structs = {}
 
+    def get_driver(self, name):
+        """Get a driver given its name
+
+        Args:
+            name (str): Driver name
+
+        Returns:
+            Driver: Driver or None if not found
+        """
+        return self._drivers.get(name)
+
     def get_normalized_compat_name(self, node):
         """Get a node's normalized compat name