MdeModulePkg: list ARM and AARCH64 as valid architectures for some modules
    
    "ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc" references
    these drivers:
    - Pci/PciBusDxe
    - Pci/EhciDxe
    - Pci/UhciDxe
    - Usb/UsbBusDxe
    - Usb/UsbKbDxe
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Laszlo Ersek <lersek@redhat.com>