wwan: add interface creation support

Add support to create (and destroy) interfaces via a new
rtnetlink kind "wwan". The responsible driver has to use
the new wwan_register_ops() to make this possible.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/wwan.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2021 Intel Corporation.
+ */
+#ifndef _UAPI_WWAN_H_
+#define _UAPI_WWAN_H_
+
+enum {
+	IFLA_WWAN_UNSPEC,
+	IFLA_WWAN_LINK_ID, /* u32 */
+
+	__IFLA_WWAN_MAX
+};
+#define IFLA_WWAN_MAX (__IFLA_WWAN_MAX - 1)
+
+#endif /* _UAPI_WWAN_H_ */