ci: Initialize ci for meta-cassini-bsp, trigger meta-cassini

Once meta-cassini-bsp resides in its own separate repository, it
need it's own CI to validate changes to the BSP code. gitlab-ci.yml
file is created. In order to verify meta-cassini-bsp,
meta-cassini-bsp pipeline is used to trigger meta-cassini pipeline.
The variables required to run jobs related to meta-cassini-bsp are
passed to the meta-cassini pipeline.

Static analysis is also disabled before passing the variables to the
meta-cassini pipeline because, when triggering the meta-cassini
pipeline from the meta-cassini-bsp pipeline, the meta-cassini code
should not have changed.

Signed-off-by: Ali Can Ozaslan <ali.oezaslan@arm.com>