feat(fwu): add a case to corrupt FWU-metadata

Add a case within the 'corrupt_gpt_bin' function specifically
tailored for corrupting FWU metadata. This case should be
adaptable for use in a test configuration aimed at
corrupting FWU metadata.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I18ff6abd2499bcdb1a32f88bc15f89c1fdd5efa0
5 files changed