MdeModulePkg/Bus/Pci/PciBusDxe: Support PCIe Resizable BAR Capability

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=313

Add PcdPcieResizableBarSupport to enable/disable PCIe Resizable
BAR Capability fearture.
Program the Resizable BAR Register if the device suports PCIe Resizable
BAR Capability and PcdPcieResizableBarSupport is TRUE.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Heng Luo <heng.luo@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h

@@ -1,7 +1,7 @@
 /** @file
   Header files and data structures needed by PCI Bus module.
 
-Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -280,6 +280,8 @@ struct _PCI_IO_DEVICE {
   // This field is used to support this case.
   //
   UINT16                                    BridgeIoAlignment;
+  UINT32                                    ResizableBarOffset;
+  UINT32                                    ResizableBarNumber;
 };
 
 #define PCI_IO_DEVICE_FROM_PCI_IO_THIS(a) \