cpu: move cc->transaction_failed to tcg_ops

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

[claudio: wrap target code around CONFIG_TCG and !CONFIG_USER_ONLY]

avoiding its use in headers used by common_ss code (should be poisoned).

Note: need to be careful with the use of CONFIG_USER_ONLY,
Message-Id: <20210204163931.7358-11-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>