feat(fwu): add FWU driver

Implemented FWU metadata load and verification APIs.
Also, exported below APIs to the platform:
1. fwu_init - Load FWU metadata in a structure. Also, set the
	      addresses of updated components in I/O policy
2. fwu_is_trial_run_state - To detect trial run or regular run

Change-Id: I67eeabb52d9275ac83be635306997b7c353727cd
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
4 files changed