For simple OSD scenario that don't require the following:
* an encrypted osd
* an osd with a backing device
* multiple osd on the same block device
The OSD will be prepared using the ceph-volume raw mode which does
not use LVM on non-pvc case.
Closes: https://github.com/rook/rook/issues/4768
Signed-off-by: Sébastien Han <seb@redhat.com>