sysemu: add set_virtual_time to accel ops

sysemu: add set_virtual_time to accel ops

We are about to remove direct calls to individual accelerators for
this information and will need a central point for plugins to hook
into time changes.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240530220610.1245424-2-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240620152220.2192768-5-alex.bennee@linaro.org>