OvmfPkg/Bhyve: consume PciHostBridgeLibScan

OvmfPkg/Bhyve: consume PciHostBridgeLibScan

Switch the Bhyve platform from the "OvmfPkg/PciHostBridgeLib" instance to
the "OvmfPkg/PciHostBridgeLibScan" instance. Currently this is a no-op
functionally; we'll customize the "PciHostBridgeLibScan" instance later.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
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: <20210526201446.12554-31-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Rebecca Cran <rebecca@bsdio.com>