mgr/cephadm: fix upgrades with nvmeof

mgr/cephadm: fix upgrades with nvmeof

Currently, nvmeof was being treated as if it used
a ceph image during upgrades. This would cause logging
of messages like (I've removed the nvmeof daemon id)

log [WRN] :     Upgrade daemon: nvmeof.<id>: Cannot redeploy
nvmeof.<id> with a new image: Supported types are: mgr, mon,
crash, osd, mds, rgw, rbd-mirror, cephfs-mirror, ceph-exporter,
iscsi, nfs

and if you had set a custom image for the
mgr/cephadm/container_image_nvmeof setting, this would
be undone as part of the upgrade process.

Fixes: https://tracker.ceph.com/issues/63127
Signed-off-by: Adam King <adking@redhat.com>