PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate

Add SPDX GPL-2.0 to all PCI files that specified the GPL version 2 license.

Remove the boilerplate GPL version 2 language, relying on the assertion in
b24413180f ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") that the SPDX identifier may be used instead of the
full boilerplate text.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/pci/pci-stub.c

@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
 /* pci-stub - simple stub driver to reserve a pci device
  *
  * Copyright (C) 2008 Red Hat, Inc.
  * Author:
  *	Chris Wright
  *
- * This work is licensed under the terms of the GNU GPL, version 2.
- *
  * Usage is simple, allocate a new id to the stub driver and bind the
  * device to it.  For example:
  *