Boot: Add TLV iterator API

Add TLV iterator API to MCUBoot as part of a partial synchronization
with the mainstream MCUBoot repository. The hash of the source commit:
61fd888a7f4d741714553f36839dd49fb0065731.

Change-Id: I817b199f4923433010253c4a201ada250f743aa8
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/bl2/ext/mcuboot/include/config-rsa.h b/bl2/ext/mcuboot/include/config-rsa.h
index 33a356b..934ab24 100644
--- a/bl2/ext/mcuboot/include/config-rsa.h
+++ b/bl2/ext/mcuboot/include/config-rsa.h
@@ -24,7 +24,7 @@
 /*
  * Original code taken from mcuboot project at:
  * https://github.com/JuulLabs-OSS/mcuboot
- * Git SHA of the original version: 4f0ea747c314547daa6b6299ccbd77ae4dee6758
+ * Git SHA of the original version: 61fd888a7f4d741714553f36839dd49fb0065731
  */
 
 /*
diff --git a/bl2/ext/mcuboot/include/flash_map/flash_map.h b/bl2/ext/mcuboot/include/flash_map/flash_map.h
index df8c6dd..16b516d 100644
--- a/bl2/ext/mcuboot/include/flash_map/flash_map.h
+++ b/bl2/ext/mcuboot/include/flash_map/flash_map.h
@@ -20,7 +20,7 @@
 /*
  * Original code taken from mcuboot project at:
  * https://github.com/JuulLabs-OSS/mcuboot
- * Git SHA of the original version: 4f0ea747c314547daa6b6299ccbd77ae4dee6758
+ * Git SHA of the original version: 61fd888a7f4d741714553f36839dd49fb0065731
  * Modifications are Copyright (c) 2018-2019 Arm Limited.
  */
 
diff --git a/bl2/ext/mcuboot/include/target.h b/bl2/ext/mcuboot/include/target.h
index 69f691a..a82ed27 100644
--- a/bl2/ext/mcuboot/include/target.h
+++ b/bl2/ext/mcuboot/include/target.h
@@ -8,7 +8,7 @@
 /*
  * Original code taken from mcuboot project at:
  * https://github.com/JuulLabs-OSS/mcuboot
- * Git SHA of the original version: 4f0ea747c314547daa6b6299ccbd77ae4dee6758
+ * Git SHA of the original version: 61fd888a7f4d741714553f36839dd49fb0065731
  */
 
 #ifndef H_TARGETS_TARGET_