vfio: add license tag to some files

Add SPDX-License-Identifier to some files missing it in hw/vfio/.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250623093053.1495509-1-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/Kconfig

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 config VFIO
     bool
     depends on LINUX

hw/vfio/meson.build

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 vfio_ss = ss.source_set()
 vfio_ss.add(files(
   'listener.c',

hw/vfio/trace-events

@@ -1,4 +1,6 @@
 # See docs/devel/tracing.rst for syntax documentation.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 # pci.c
 vfio_intx_interrupt(const char *name, char line) " (%s) Pin %c"

hw/vfio/trace.h

@@ -1 +1,4 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
 #include "trace/trace-hw_vfio.h"