Create a qemuDomainAddChardevTLSObjects which will encapsulate the
qemuDomainGetChardevTLSObjects and qemuDomainAddTLSObjects so that
the callers don't need to worry about the props.

Move the dev->type and haveTLS checks in to the Add function to avoid
an unnecessary call to qemuDomainAddTLSObjects
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>