PCI Serial Device Info. It is an array of Device, Function, and Power Management
information that describes the path that contains zero or more PCI to PCI bridges
followed by a PCI serial device. Each array entry is 4-bytes in length. The
first byte is the PCI Device Number, then second byte is the PCI Function Number,
and the last two bytes are the offset to the PCI power management capabilities
register used to manage the D0-D3 states. If a PCI power management capabilities
register is not present, then the last two bytes in the offset is set to 0. The
array is terminated by an array entry with a PCI Device Number of 0xFF. For a
non-PCI fixed address serial device, such as an ISA serial device, the value is 0xFF.
Pci Serial Device Info

PCD Information

Name	Token Space	Token number	Data Type	Default Value
PcdSerialPciDeviceInfo	gEfiMdeModulePkgTokenSpaceGuid	0x00010067	VOID*	{0xFF}