EmulatorPkg/MpService: StartupAllAPs should verify processor state before setting state
    
    if any enabled APs are not in idle state, StartupAllAPs() should return immediately,
    and must not change the other idled processor state. so we checked the state before
    changed them.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
    Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
    
    git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16416 6f19259b-4bc3-4df7-8a09-765794883524