virtcontainers/network: Change signature of Enpoint Attach method

In order to use the device manager and receiver from the network enpoints,
the signature of the Attach method must change to revice a Sandbox instead of
a Hypervisor, this way devices can be added through the device manager API.

Signed-off-by: Julio Montes <julio.montes@intel.com>

src/runtime/virtcontainers/macvtap_endpoint.go

@@ -58,8 +58,9 @@ func (endpoint *MacvtapEndpoint) SetProperties(properties NetworkInfo) {
 }
 
 // Attach for macvtap endpoint passes macvtap device to the hypervisor.
-func (endpoint *MacvtapEndpoint) Attach(h hypervisor) error {
+func (endpoint *MacvtapEndpoint) Attach(s *Sandbox) error {
 	var err error
+	h := s.hypervisor
 
 	endpoint.VMFds, err = createMacvtapFds(endpoint.EndpointProperties.Iface.Index, int(h.hypervisorConfig().NumVCPUs))
 	if err != nil {