UefiCpuPkg/CpuDxe: Copy two functions from PciHostBridge

UefiCpuPkg/CpuDxe: Copy two functions from PciHostBridge

Copy AddMemoryMappedIoSpace() and IntersectMemoryDescriptor() from
MdeModulePkg\Bus\Pci\PciHostBridgeDxe\PciHostBridge.c.

https://bugzilla.tianocore.org/show_bug.cgi?id=390

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>