Boot: Synchronize MCUBoot code base

Perform a partial synchronization between the MCUBoot files in TF-M
and in the original repository. The hash of the source commit in the
original repository: 4f0ea747c314547daa6b6299ccbd77ae4dee6758.

Main changes:
- Remove current_image global variable and make it part
  of the boot state struct
- Update routines to receive the boot state by parameter
- Refactor dependency check functions
- Reorganize the flash map and related files
- Fix swap status control

Change-Id: Ibe948792b306e96282fb82447bb3f05a0c6389ef
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/bl2/ext/mcuboot/bootutil/src/image_rsa.c b/bl2/ext/mcuboot/bootutil/src/image_rsa.c
index ae71d9b..08ef6f5 100644
--- a/bl2/ext/mcuboot/bootutil/src/image_rsa.c
+++ b/bl2/ext/mcuboot/bootutil/src/image_rsa.c
@@ -20,7 +20,7 @@
 /*
  * Original code taken from mcuboot project at:
  * https://github.com/JuulLabs-OSS/mcuboot
- * Git SHA of the original version: 3c469bc698a9767859ed73cd0201c44161204d5c
+ * Git SHA of the original version: 4f0ea747c314547daa6b6299ccbd77ae4dee6758
  * Modifications are Copyright (c) 2018-2019 Arm Limited.
  */