dm: Add a library to provide simple device-tree access

This Python library provides a way to access the contents of the device
tree. It uses fdtget, so is inefficient for larger device tree files.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/dtoc/.gitignore b/tools/dtoc/.gitignore
new file mode 100644
index 0000000..0d20b64
--- /dev/null
+++ b/tools/dtoc/.gitignore
@@ -0,0 +1 @@
+*.pyc