feat(tfut): add build support for unit testing

With this patch, the CI is now capable of configuring and building
unit tests by adding the proper component to the test group
variable.

Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Signed-off-by: Edward Potapov <edward.potapov@arm.com>
Change-Id: Iba487106a9dc5aa8358b358d385599a36f38b121
4 files changed