This is follow up on discussion of PR:
https://github.com/kernelci/kernelci-pipeline/pull/377
https://github.com/kernelci/kernelci-core/pull/2258



Now workflow of enabling LAVA lab is simplified:
LAVA lab need to enable one or two tokens (two a bit more secure,
as one will be used to submit job, another for callback),
and provide name(description) of one of tokens to specify
in pipeline.yaml.
Also in toml file we need to specify callback token value.

Signed-off-by: Denys Fedoryshchenko <denys.f@collabora.com>