Add note about deprecated setting of mm_time
Add note about deprecated setting of mm_time

spice-server now ignores this mm_time value and sets it itself as it
maintains its own timer (see spice-server commit c541d7e2 'Remove guest
side video time-stamping')

fgouget/xf86-video-qxl,fgouget/xf86-video-qxl,fgouget/xf86-video-qxl,fgouget/xf86-video-qxl