ci: create groups for Arm platforms and partner boards

Currently there are two l1 test groups which does non fvp/juno platform
boot tests, few of them are Arm reference platforms and few are partner
boards. Create two l2 groups one each for Arm platforms and partner
boards.

- tf-l1-boot-tests-plat : tf-l2-boot-tests-partner-boards
- tf-plat-tests : tf-l2-boot-tests-arm-plats

Change-Id: I8cfa16de1dd09981b5a5ffdc9cf79b19e789b453
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
(cherry picked from commit a14b3977f3fed902a5f7512a40fbeb63d16ca31f)
9 files changed