Always use TSO, per the Oracle 2015 manual.
This is slightly less restrictive than the TCG_MO_ALL default,
and happens to match the i386 model, which will eliminate a few
extra barriers on that host.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>