panfrost/ci: Initial commit

panfrost/ci: Initial commit

These files implement running almost all of deqp-gles2 on Chomebooks of
the rk3399-gru-kevin type in Collabora's LAVA lab.

The approach follows what is currently being used for virglrenderer,
but scheduling the actual test jobs via LAVA.

We start by building a container in Docker that contains a suitable
rootfs and kernel for the DUT, deqp and all dependencies for building
Mesa itself.

The Mesa is built and the rootfs, deqp and Mesa are combined in a cpio
ramdisk. A LAVA job is generated, submitted to LAVA and the results are
processed by simply comparing them to the expectations that are stored
in git. Any code that changes the expectations (hopefully tests are
fixed) needs to also update the expectations file.

The next step is adding support for other devices, possibly in other
LAVA labs.

In order to use this, the repository has to be configured to run the
gitlab-ci.yaml file from the panfrost/ci dir, and a LAVA token needs to
be setup.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>