Docker, CI: Add vexpress_fvp / vexpress_fvp_bloblist support

Docker, CI: Add vexpress_fvp / vexpress_fvp_bloblist support

This adds the vexpress_fvp and vexpress_fvp_bloblist platforms to the
list of platforms we test via emulator in CI. In order to do this we
need to first have our container runtime have TF-A builds for the
vexpress_fvp platform, both with and without transfer list support as
well as installing "telnet" so that we can access console. In the CI
files we check for the existence of /opt/tf-a/${TEST_PY_BD} and if
found, copy bl1.bin and fip.bin to /tmp and set the variables so that we
can later run FVP to run.

Note that we currently disable the hostfs (semihosting) tests as they
trigger a bug in FVP. This has been reported upstream, and can be
enabled when fixed.

Reviewed-by: Harrison Mutai <harrison.mutai@arm.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Tom Rini <trini@konsulko.com>