fdt: add prototype for fdt_increase_size()

Add a prototype for fdt_increase_size() so that anyone can call it.

Signed-off-by: Timur Tabi <timur@freescale.com>
diff --git a/include/fdt_support.h b/include/fdt_support.h
index cefc990..382f632 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -79,6 +79,7 @@
 
 void set_working_fdt_addr(void *addr);
 int fdt_resize(void *blob);
+int fdt_increase_size(void *fdt, int add_len);
 
 int fdt_fixup_nor_flash_size(void *blob);