dm: core: fix typo in device.h

Replace 'a the' with 'the' in include/dm/device.h.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/device.h b/include/dm/device.h
index ac3b6c1..993c9e6 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -823,7 +823,7 @@
 	     _ret = device_next_child_err(&dev))
 
 /**
- * dm_scan_fdt_dev() - Bind child device in a the device tree
+ * dm_scan_fdt_dev() - Bind child device in the device tree
  *
  * This handles device which have sub-nodes in the device tree. It scans all
  * sub-nodes and binds drivers for each node where a driver can be found.