"OvmfPkg/Include/IndustryStandard/Virtio095.h" defines the macro
VIRTIO_SUBSYSTEM_CONSOLE with value 3; other locations in the tree already
use it (such as ArmVirtPkg/PlatformBootManagerLib,
OvmfPkg/VirtioSerialDxe). We should use it in
OvmfPkg/PlatformBootManagerLib too, rather than the naked constant 3.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>