docs: Deprecate the qemu-system-microblazeel binary

docs: Deprecate the qemu-system-microblazeel binary

The (former big-endian only) binary qemu-system-microblaze can
handle both endiannesses nowadays, so we don't need the separate
qemu-system-microblazeel binary for little endian anymore. Let's
deprecate it to avoid unnecessary compilation and test time in
the future.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20250515132019.569365-5-thuth@redhat.com>