MdeModulePkg/PciHostBridgeLib.h: add address Translation

MdeModulePkg/PciHostBridgeLib.h: add address Translation

Add Translation field to PCI_ROOT_BRIDGE_APERTURE. Translation is used
to represent the difference between device address and host address,
if they are not the same on some platforms.

In UEFI 2.7, "Address Translation Offset" is "Offset to apply to the
Starting address to convert it to a PCI address".  This means:

  Translation = device address - host address

So we also use the above calculation for this Translation field to
keep consistent.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Signed-off-by: Yi Li <phoenix.liyi@huawei.com>
Reviewed-by: Ni Ruiyu <ruiyu.ni@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>