tf-a-tftf-main: add "alias" prop for tf-a-ci-gateway subjobs

Updated the "tf-a-ci-gateway" subjobs by introducing the "alias"
property to highlight the test group(s) for build/run.
Additionally, reorganized the test groups to execute them within a
distinct "tf-a-ci-gateway" job.

Change-Id: I4ae565b364c0153ce00ad65ce48a53354347073b
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
1 file changed