PciEmulation configuration
--------------------------
Installation of various NonDiscoverable devices via PciEmulation driver is performed
via set of PCDs. Following are available:

 gMarvellTokenSpaceGuid.PcdPciEXhci

Indicates, which Xhci devices are used.

 gMarvellTokenSpaceGuid.PcdPciEAhci

Indicates, which Ahci devices are used.

 gMarvellTokenSpaceGuid.PcdPciESdhci

Indicates, which Sdhci devices are used.

All above PCD's correspond to hardware description in a dedicated structure:

STATIC PCI_E_PLATFORM_DESC A70x0PlatDescTemplate

in Platforms/Marvell/PciEmulation/PciEmulation.c file. It comprises device
count, base addresses, register region size and DMA-coherency type.

Examples
--------
Assuming we want to enable second XHCI port and one SDHCI port on Armada
70x0 board, following needs to be declared:

  gMarvellTokenSpaceGuid.PcdPciEXhci|{ 0x0 0x1 }
  gMarvellTokenSpaceGuid.PcdPciESdhci|{ 0x1 }