OvmfPkg/PciHostBridgeLibScan: remove PcdOvmfHostBridgePciDevId
    
    The "OvmfPkg/Library/PciHostBridgeLibScan/PciHostBridgeLibScan.inf"
    instance is used in the following platforms in edk2:
    
      OvmfPkg/Bhyve/BhyveX64.dsc
      OvmfPkg/OvmfXen.dsc
    
    Neither Bhyve nor Xen provide a Q35 board, therefore the expression
    
      PcdGet16 (PcdOvmfHostBridgePciDevId) != INTEL_Q35_MCH_DEVICE_ID
    
    always evaluates to TRUE, in the PciHostBridgeLibScan instance.
    
    Replace the expression with constant TRUE, eliminating the PCD dependency.
    
    (In effect, this reports that the root bridge being registered does not
    support extended PCI config space.)
    
    Cc: Anthony Perard <anthony.perard@citrix.com>
    Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
    Cc: Jordan Justen <jordan.l.justen@intel.com>
    Cc: Julien Grall <julien@xen.org>
    Cc: Peter Grehan <grehan@freebsd.org>
    Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
    Cc: Rebecca Cran <rebecca@bsdio.com>
    Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2122
    Signed-off-by: Laszlo Ersek <lersek@redhat.com>
    Message-Id: <20210526201446.12554-35-lersek@redhat.com>
    Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>