Build: Adjust configuration order

Reorder the configuration steps, to provide more intuitive
configuration. Invert the current order, and remove the use of FORCE to
create a configuration additively instead of using overriding. Allows
cmake command-line variables to override all other options as is
expected.

Change-Id: I64730b7db230cdaf2f86f1d27d882dc9111607be
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Signed-off-by: Raef Coles <raef.coles@arm.com>
21 files changed