ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause

I was intending to make all the Netlink Spec code BSD-3-Clause
to ease the adoption but it appears that:
 - I fumbled the uAPI and used "GPL WITH uAPI note" there
 - it gives people pause as they expect GPL in the kernel
As suggested by Chuck re-license under dual. This gives us benefit
of full BSD freedom while fulfilling the broad "kernel is under GPL"
expectations.

Link: https://lore.kernel.org/all/20230304120108.05dd44c5@kernel.org/
Link: https://lore.kernel.org/r/20230306200457.3903854-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

Documentation/netlink/genetlink-c.yaml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 %YAML 1.2
 ---
 $id: http://kernel.org/schemas/netlink/genetlink-c.yaml#

Documentation/netlink/genetlink-legacy.yaml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 %YAML 1.2
 ---
 $id: http://kernel.org/schemas/netlink/genetlink-legacy.yaml#

Documentation/netlink/genetlink.yaml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 %YAML 1.2
 ---
 $id: http://kernel.org/schemas/netlink/genetlink-legacy.yaml#

Documentation/netlink/specs/ethtool.yaml

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
 name: ethtool
 
 protocol: genetlink-legacy

Documentation/netlink/specs/fou.yaml

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
 name: fou
 
 protocol: genetlink-legacy

Documentation/netlink/specs/netdev.yaml

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
 name: netdev
 
 doc:

Documentation/userspace-api/netlink/specs.rst

@@ -24,6 +24,9 @@ YAML specifications can be found under ``Documentation/netlink/specs/``
 This document describes details of the schema.
 See :doc:`intro-specs` for a practical starting guide.
 
+All specs must be licensed under ``GPL-2.0-only OR BSD-3-Clause``
+to allow for easy adoption in user space code.
+
 Compatibility levels
 ====================
 

include/uapi/linux/fou.h

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause */
 /* Do not edit directly, auto-generated from: */
 /*	Documentation/netlink/specs/fou.yaml */
 /* YNL-GEN uapi header */

include/uapi/linux/netdev.h

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause */
 /* Do not edit directly, auto-generated from: */
 /*	Documentation/netlink/specs/netdev.yaml */
 /* YNL-GEN uapi header */

net/core/netdev-genl-gen.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BSD-3-Clause
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /* Do not edit directly, auto-generated from: */
 /*	Documentation/netlink/specs/netdev.yaml */
 /* YNL-GEN kernel source */