qemu: domain: Setup secret for TLS key for nbd/vxhs disks
qemu: domain: Setup secret for TLS key for nbd/vxhs disks

Setup the TLS secret when preparing a virStorageSource for use.

https://bugzilla.redhat.com/show_bug.cgi?id=1602328

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Eric Blake <a9da18479c871fe903d9590822cfe2629c6a4d11@redhat.com>

crobinso/libvirt,jardasgit/libvirt,jardasgit/libvirt,jfehlig/libvirt,libvirt/libvirt,crobinso/libvirt,olafhering/libvirt,jardasgit/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,zippy2/libvirt,nertpinx/libvirt,jfehlig/libvirt,olafhering/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,jardasgit/libvirt,crobinso/libvirt,jfehlig/libvirt,zippy2/libvirt,crobinso/libvirt,olafhering/libvirt,jardasgit/libvirt,nertpinx/libvirt