dm: core: Rename dev_has_of_node() to dev_has_ofnode()

We use 'ofnode' rather than 'of_node' in U-Boot. Rename this function to
fit.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/device.h b/include/dm/device.h
index a0c1752..b15a14e 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -200,7 +200,7 @@
 	return ofnode_to_offset(dev->node);
 }
 
-static inline bool dev_has_of_node(struct udevice *dev)
+static inline bool dev_has_ofnode(struct udevice *dev)
 {
 	return ofnode_valid(dev->node);
 }