RHEL 7 does not ship tgtadm or tgtd so they cannot be used in the
deploy ramdisk. This change separates the tgt-specific parts of
the ramdisk into their own element, and adds a new one that supports
targetcli instead.
For now, the tgt implementation can only be used with traditional
busybox ramdisks and the targetcli one can only be used with dracut.
This is because dracut is primarily used for RHEL right now so it
makes sense to keep the dependencies simple. If there is a future
desire to mix and match the implementations that could be done, but
it would require users to explicitly select between tgt and
targetcli.
Change-Id: I4f99c91016287e08d836095c2f2261de8b45abdc
Co-Authored-By: James Slagle <jslagle@redhat.com>
