device property: Constify fwnode APIs that uses fwnode_get_next_parent()

Due to fwnode_get_next_parent() used to be called against the parameters
of some of fwnode APIs those parameters have no const qualifier. However,
after switching to fwnode_for_each_parent_node() API now it's possible to
constify the parameters. Do it for good.

The affected functions are:

	fwnode_get_next_parent_dev()
	fwnode_get_nth_parent()
	fwnode_is_ancestor_of()

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/base/property.c

@@ -594,7 +594,7 @@ EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
  * The caller of this function is expected to call put_device() on the returned
  * device when they are done.
  */
-struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)
+struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode)
 {
 	struct fwnode_handle *parent;
 	struct device *dev;
@@ -639,8 +639,7 @@ EXPORT_SYMBOL_GPL(fwnode_count_parents);
  * The caller is responsible for calling fwnode_handle_put() for the returned
  * node.
  */
-struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
-					    unsigned int depth)
+struct fwnode_handle *fwnode_get_nth_parent(const struct fwnode_handle *fwnode, unsigned int depth)
 {
 	struct fwnode_handle *parent;
 
@@ -664,7 +663,7 @@ EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
  *
  * Returns true if @ancestor is an ancestor of @child. Otherwise, returns false.
  */
-bool fwnode_is_ancestor_of(struct fwnode_handle *ancestor, struct fwnode_handle *child)
+bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child)
 {
 	struct fwnode_handle *parent;
 

include/linux/property.h

@@ -91,11 +91,10 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
 	for (parent = fwnode_get_parent(fwnode); parent;	\
 	     parent = fwnode_get_next_parent(parent))
 
-struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode);
-unsigned int fwnode_count_parents(const struct fwnode_handle *fwn);
-struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn,
-					    unsigned int depth);
-bool fwnode_is_ancestor_of(struct fwnode_handle *ancestor, struct fwnode_handle *child);
+struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode);
+unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_nth_parent(const struct fwnode_handle *fwnode, unsigned int depth);
+bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child);
 struct fwnode_handle *fwnode_get_next_child_node(
 	const struct fwnode_handle *fwnode, struct fwnode_handle *child);
 struct fwnode_handle *fwnode_get_next_available_child_node(