fdt: Export the fdt_find_or_add_subnode() function

This function is useful for ensuring that a node exists. Export it so it
can be used more widely.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/common/fdt_support.c b/common/fdt_support.c
index 3f64156..46a15e7 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -113,7 +113,8 @@
 }
 
 /**
- * fdt_find_or_add_subnode - find or possibly add a subnode of a given node
+ * fdt_find_or_add_subnode() - find or possibly add a subnode of a given node
+ *
  * @fdt: pointer to the device tree blob
  * @parentoffset: structure block offset of a node
  * @name: name of the subnode to locate
@@ -121,8 +122,7 @@
  * fdt_subnode_offset() finds a subnode of the node with a given name.
  * If the subnode does not exist, it will be created.
  */
-static int fdt_find_or_add_subnode(void *fdt, int parentoffset,
-				   const char *name)
+int fdt_find_or_add_subnode(void *fdt, int parentoffset, const char *name)
 {
 	int offset;
 
diff --git a/include/fdt_support.h b/include/fdt_support.h
index 2e0adf3..9ada2e4 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -64,6 +64,8 @@
 int fdt_pci_dma_ranges(void *blob, int phb_off, struct pci_controller *hose);
 #endif
 
+int fdt_find_or_add_subnode(void *fdt, int parentoffset, const char *name);
+
 /**
  * Add board-specific data to the FDT before booting the OS.
  *