edtlib: finish adding type annotations

This concludes the type annotations for the public API for the module,
along with the relevant internal state. It's not worth type annotating
the internal backwards compatibility shim for !include.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>

scripts/dts/python-devicetree/src/devicetree/edtlib.py

@@ -3173,7 +3173,7 @@ class _BindingLoader(Loader):
 # include/devicetree.h.
 #
 
-_DEFAULT_PROP_TYPES = {
+_DEFAULT_PROP_TYPES: Dict[str, str] = {
     "compatible": "string-array",
     "status": "string",
     "reg": "array",
@@ -3185,18 +3185,20 @@ class _BindingLoader(Loader):
     "interrupt-controller": "boolean",
 }
 
-_STATUS_ENUM = "ok okay disabled reserved fail fail-sss".split()
+_STATUS_ENUM: List[str] = "ok okay disabled reserved fail fail-sss".split()
 
-def _raw_default_property_for(name):
-    ret = {
+def _raw_default_property_for(
+        name: str
+) -> Dict[str, Union[str, bool, List[str]]]:
+    ret: Dict[str, Union[str, bool, List[str]]] = {
         'type': _DEFAULT_PROP_TYPES[name],
         'required': False,
     }
     if name == 'status':
         ret['enum'] = _STATUS_ENUM
     return ret
 
-_DEFAULT_PROP_BINDING = Binding(
+_DEFAULT_PROP_BINDING: Binding = Binding(
     None, {},
     raw={
         'properties': {
@@ -3207,14 +3209,14 @@ def _raw_default_property_for(name):
     require_compatible=False, require_description=False,
 )
 
-_DEFAULT_PROP_SPECS = {
+_DEFAULT_PROP_SPECS: Dict[str, PropertySpec] = {
     name: PropertySpec(name, _DEFAULT_PROP_BINDING)
     for name in _DEFAULT_PROP_TYPES
 }
 
 # A set of vendor prefixes which are grandfathered in by Linux,
 # and therefore by us as well.
-_VENDOR_PREFIX_ALLOWED = set([
+_VENDOR_PREFIX_ALLOWED: Set[str] = set([
     "at25", "bm", "devbus", "dmacap", "dsa",
     "exynos", "fsia", "fsib", "gpio-fan", "gpio-key", "gpio", "gpmc",
     "hdmi", "i2c-gpio", "keypad", "m25p", "max8952", "max8997",