scsi-hd: qdev properties for disk geometry

scsi-hd: qdev properties for disk geometry

Geometry needs to be qdev properties, because it belongs to the
disk's guest part.

Maintain backward compatibility exactly like for serial: fall back to
DriveInfo's geometry, set with -drive cyls=...

Do this only for scsi-hd.  scsi-disk is legacy.  scsi-cd doesn't have
a geometry.  scsi-block should get geometry from the host disk.

Bonus: info qtree now shows the geometry.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>