Boot: Introduce new protected TLV format

Introduce new protected TLV format in MCUBoot as part of a partial
synchronization with the mainstream MCUBoot repository. The hash of the
source commit: 510fddb8e06d76e2442b2a4603d3e1cbefe28be4.

Adapt image.py Python script to the new TLV format.

Change-Id: I760927cea3fbc66536623c1ed6606debb97a2e74
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/bl2/ext/mcuboot/bootutil/src/bootutil_misc.c b/bl2/ext/mcuboot/bootutil/src/bootutil_misc.c
index 870420e..e295fa8 100644
--- a/bl2/ext/mcuboot/bootutil/src/bootutil_misc.c
+++ b/bl2/ext/mcuboot/bootutil/src/bootutil_misc.c
@@ -20,7 +20,7 @@
 /*
  * Original code taken from mcuboot project at:
  * https://github.com/JuulLabs-OSS/mcuboot
- * Git SHA of the original version: 61fd888a7f4d741714553f36839dd49fb0065731
+ * Git SHA of the original version: 510fddb8e06d76e2442b2a4603d3e1cbefe28be4
  * Modifications are Copyright (c) 2019 Arm Limited.
  */