of_graph: add of_graph_is_present()

#include "of_private.h"

/**

 * of_graph_is_present() - check graph's presence

 * @node: pointer to device_node containing graph port

 *

 * Return: True if @node has a port or ports (with a port) sub-node,

 * false otherwise.

 */

bool of_graph_is_present(const struct device_node *node)

{

	struct device_node *ports, *port;

	ports = of_get_child_by_name(node, "ports");

	if (ports)

		node = ports;

	port = of_get_child_by_name(node, "port");

	of_node_put(ports);

	of_node_put(port);

	return !!port;

}

EXPORT_SYMBOL(of_graph_is_present);

/**

 * of_property_count_elems_of_size - Count the number of elements in a property

 *

	     child = of_graph_get_next_endpoint(parent, child))

#ifdef CONFIG_OF

bool of_graph_is_present(const struct device_node *node);

int of_graph_parse_endpoint(const struct device_node *node,

				struct of_endpoint *endpoint);

int of_graph_get_endpoint_count(const struct device_node *np);

					     u32 port, u32 endpoint);

#else

static inline bool of_graph_is_present(const struct device_node *node)

{

	return false;

}

static inline int of_graph_parse_endpoint(const struct device_node *node,

					struct of_endpoint *endpoint)

{