nand: Bump vmstate version after changing structure.

Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>
diff --git a/hw/nand.c b/hw/nand.c
index 764356a..f5f204a 100644
--- a/hw/nand.c
+++ b/hw/nand.c
@@ -308,9 +308,9 @@
 
 static const VMStateDescription vmstate_nand = {
     .name = "nand",
-    .version_id = 0,
-    .minimum_version_id = 0,
-    .minimum_version_id_old = 0,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
     .pre_save = nand_pre_save,
     .post_load = nand_post_load,
     .fields      = (VMStateField[]) {