unix: add missing IFLA_* consts on linux

Change-Id: Ib221d98f8d7e5aac7ff2db207cdd92145fe1dc60
Reviewed-on: https://go-review.googlesource.com/c/sys/+/503715
Run-TryBot: Tobias Klauser <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Auto-Submit: Tobias Klauser <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>

Author: tklauser

unix/linux/types.go

@@ -1517,6 +1517,10 @@ const (
 	IFLA_GRO_MAX_SIZE                          = C.IFLA_GRO_MAX_SIZE
 	IFLA_TSO_MAX_SIZE                          = C.IFLA_TSO_MAX_SIZE
 	IFLA_TSO_MAX_SEGS                          = C.IFLA_TSO_MAX_SEGS
+	IFLA_ALLMULTI                              = C.IFLA_ALLMULTI
+	IFLA_DEVLINK_PORT                          = C.IFLA_DEVLINK_PORT
+	IFLA_GSO_IPV4_MAX_SIZE                     = C.IFLA_GSO_IPV4_MAX_SIZE
+	IFLA_GRO_IPV4_MAX_SIZE                     = C.IFLA_GRO_IPV4_MAX_SIZE
 	IFLA_PROTO_DOWN_REASON_UNSPEC              = C.IFLA_PROTO_DOWN_REASON_UNSPEC
 	IFLA_PROTO_DOWN_REASON_MASK                = C.IFLA_PROTO_DOWN_REASON_MASK
 	IFLA_PROTO_DOWN_REASON_VALUE               = C.IFLA_PROTO_DOWN_REASON_VALUE