tests/docker: introduce debian-riscv64-test-cross

Cross building QEMU for riscv64 still involves messing about with sid
and ports. However for building tests we can have a slimmer compiler
only container which should be more stable.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220225172021.3493923-7-alex.bennee@linaro.org>
4 files changed