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>
19 files changed