tests/functional: Explicit endianness of microblaze assets

tests/functional: Explicit endianness of microblaze assets

The archive used in test_microblaze_s3adsp1800.py (testing a
big-endian target) contains a big-endian kernel. Rename using
the _BE suffix.

Similarly, the archive in test_microblazeel_s3adsp1800 (testing
a little-endian target) contains a little-endian kernel. Rename
using _LE suffix.

These changes will help when adding cross-endian kernel tests.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20250206131052.30207-13-philmd@linaro.org>