Support group mods and group stats requests.

Added support for match IPv4 destination address.

Change-Id: I8693299f29ba3c45f61b936877d443218e5410c4
diff --git a/internal/pkg/openflow/flowMod.go b/internal/pkg/openflow/flowMod.go
index 5424c12..08c0b98 100644
--- a/internal/pkg/openflow/flowMod.go
+++ b/internal/pkg/openflow/flowMod.go
@@ -26,6 +26,7 @@
 	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 	"github.com/opencord/voltha-protos/v3/go/openflow_13"
 	"github.com/opencord/voltha-protos/v3/go/voltha"
+	"net"
 )
 
 var oxmMap = map[string]int32{
@@ -119,6 +120,10 @@
 			field.Value = &voltha.OfpOxmOfbField_IpProto{
 				IpProto: uint32(val.(ofp.IpPrototype)),
 			}
+		case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IPV4_DST:
+			field.Value = &voltha.OfpOxmOfbField_Ipv4Dst{
+				Ipv4Dst: binary.BigEndian.Uint32(val.(net.IP)),
+			}
 		case voltha.OxmOfbFieldTypes_OFPXMT_OFB_UDP_SRC:
 			field.Value = &voltha.OfpOxmOfbField_UdpSrc{
 				UdpSrc: uint32(val.(uint16)),
@@ -355,6 +360,10 @@
 			field.Value = &voltha.OfpOxmOfbField_IpProto{
 				IpProto: uint32(val.(ofp.IpPrototype)),
 			}
+		case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IPV4_DST:
+			field.Value = &voltha.OfpOxmOfbField_Ipv4Dst{
+				Ipv4Dst: binary.BigEndian.Uint32(val.(net.IP)),
+			}
 		case voltha.OxmOfbFieldTypes_OFPXMT_OFB_UDP_SRC:
 			field.Value = &voltha.OfpOxmOfbField_UdpSrc{
 				UdpSrc: uint32(val.(uint16)),