gen_fvp_*_yaml.sh: Add Gerrit metadata for LAVA job

To be able to cross-ref LAVA job run to Gerrit change which started it,
if any.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I64085510af8f81d6bf4cb965fd517089c961389c
3 files changed