device property: Add a macro for interating over graph endpoints

Add a convenience macro for iterating over graph endpoints. Iterating over
graph endpoints using fwnode_graph_get_next_endpoint() is a recurring
pattern, and this macro allows calling that function in a slightly more
convenient way. For instance,

for (child = NULL;
(child = fwnode_graph_get_next_endpoint(fwnode, child)); )

becomes

fwnode_graph_for_each_endpoint(fwnode, child)

Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

include/linux/property.h

···
 fwnode_graph_get_remote_node(const struct fwnode_handle *fwnode, u32 port,
 			     u32 endpoint);
 
+#define fwnode_graph_for_each_endpoint(fwnode, child)			\
+	for (child = NULL;						\
+	     (child = fwnode_graph_get_next_endpoint(fwnode, child)); )
+
 int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 				struct fwnode_endpoint *endpoint);