OvmfPkg: Add CpuPageTableLib required by MpInitLib.
    
    Add CpuPageTableLib required by MpInitLib in OvmfPkg.
    
    Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
    Reviewed-by: Ray Ni <ray.ni@intel.com>
    Acked-by: Jiewen Yao <jiewen.yao@intel.com>