Introduce 2 APIs to support emulator threads in remote driver.
    1) remoteDomainPinEmulator: call driver api, such as qemudDomainPinEmulator.
    2) remoteDomainGetEmulatorPinInfo: call driver api, such as qemudDomainGetEmulatorPinInfo.
They are similar to remoteDomainPinVcpuFlags and remoteDomainGetVcpuPinInfo.
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>