fdt_support: Add fdt_delete_disabled_nodes() and use in Turris MOX

Move Turris MOX specific remove_disabled_nodes() to fdt_support with
name fdt_delete_disabled_nodes(), so that others can potentially use it.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/include/fdt_support.h b/include/fdt_support.h
index d405867..8ec461a 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -228,6 +228,8 @@
 int fdt_shrink_to_minimum(void *blob, uint extrasize);
 int fdt_increase_size(void *fdt, int add_len);
 
+int fdt_delete_disabled_nodes(void *blob);
+
 int fdt_fixup_nor_flash_size(void *blob);
 
 struct node_info;