i386: expose floppy drive CMOS type

Make it possible to query the CMOS type of a floppy drive outside of the
source file where it's defined.

It will allow to properly populate the corresponding ACPI objects and
thus enable Windows on BIOS-less systems to access the floppy drives.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: John Snow <jsnow@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Kevin O'Connor <kevin@koconnor.net>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
