Most of the changes consist in using the new code owners terminology
(from [1]).

[1] https://developer.trustedfirmware.org/w/collaboration/project-maintenance-process/

Change-Id: Icead20e9335af12aa47d3f1ac5d04ca157b20c82
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>