Reorg TCG AccelOpsClass initialization to emphasis icount
mode share more code with single-threaded TCG.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323171751.78612-7-philippe.mathieu.daude@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>