MdePkg: Define structures for Resizable BAR Capability

MdePkg: Define structures for Resizable BAR Capability

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3138

Define structures for Resizable BAR Capability in
MdePkg/Include/IndustryStandard/PciExpress21.h,
Change ShellPkg/Library/UefiShellDebug1CommandsLib/Pci.c
to use new structures.

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>
Reviewed-by: Liming Gao <liming.gao@intel.com>