dm: Tidy up four minor code nits

There is a spelling mistake and two functions are missing comments
altogether. Also the flags declaration is correct, but doesn't follow
style. Finally, the uclass_get_device() function has some errors in
its documentation.

Fix these problems.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/include/dm/root.h b/include/dm/root.h
index 3018bc8..a4826a6 100644
--- a/include/dm/root.h
+++ b/include/dm/root.h
@@ -41,7 +41,7 @@
 int dm_scan_fdt(const void *blob);
 
 /**
- * dm_init() - Initialize Driver Model structures
+ * dm_init() - Initialise Driver Model structures
  *
  * This function will initialize roots of driver tree and class tree.
  * This needs to be called before anything uses the DM