sim: Fix ordering on TlvFlags

This enum ended up with some fields out of order.  Fix the order.  No
impact to the code, as each enum entry has a specific value, this just
makes the whole enum more consistent.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index 6680b4f..051e72a 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -67,8 +67,8 @@
     PIC = 0x01,
     NON_BOOTABLE = 0x02,
     ENCRYPTED_AES128 = 0x04,
-    RAM_LOAD = 0x20,
     ENCRYPTED_AES256 = 0x08,
+    RAM_LOAD = 0x20,
 }
 
 /// A generator for manifests.  The format of the manifest can be either a