gitlab-ci: Use functional container job names

gitlab-ci: Use functional container job names

This makes it easier to tell which job is which in a pipeline.

v2:
* Use lava_arm{64,hf} instead of arm{64,hf}_lava to keep these jobs
  together in pipeline overviews

Reviewed-by: Eric Anholt <eric@anholt.net> # v1
Reviewed-by: Eric Engestrom <eric@engestrom.ch>