scripts: gen_defines: rearrange some internals

Consolidate child helper macros into a single function. No functional
changes expected.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
diff --git a/scripts/dts/gen_defines.py b/scripts/dts/gen_defines.py
index 7cff885..5c3b950 100755
--- a/scripts/dts/gen_defines.py
+++ b/scripts/dts/gen_defines.py
@@ -132,8 +132,7 @@
                 out_dt_define(f"{node.z_path_id}_PARENT",
                               f"DT_{node.parent.z_path_id}")
 
-            write_child_functions(node)
-            write_child_functions_status_okay(node)
+            write_children(node)
             write_dep_info(node)
             write_idents_and_existence(node)
             write_bus(node)
@@ -531,9 +530,8 @@
             f"{node.z_path_id}_COMPAT_MATCHES_{str2ident(compat)}", 1)
 
 
-def write_child_functions(node):
-    # Writes macro that are helpers that will call a macro/function
-    # for each child node.
+def write_children(node):
+    # Writes helper macros for dealing with node's children.
 
     out_dt_define(f"{node.z_path_id}_FOREACH_CHILD(fn)",
             " ".join(f"fn(DT_{child.z_path_id})" for child in
@@ -543,10 +541,6 @@
             " ".join(f"fn(DT_{child.z_path_id}, __VA_ARGS__)" for child in
                 node.children.values()))
 
-def write_child_functions_status_okay(node):
-    # Writes macros that are helpers that will call a macro/function
-    # for each child node with status "okay".
-
     functions = ''
     functions_args = ''
     for child in node.children.values():