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
b24413180f56 ("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>
diff --git a/drivers/pci/dwc/pcie-histb.c b/drivers/pci/dwc/pcie-histb.c
index 33b01b73..70b5c0b 100644
--- a/drivers/pci/dwc/pcie-histb.c
+++ b/drivers/pci/dwc/pcie-histb.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * PCIe host controller driver for HiSilicon STB SoCs
  *
@@ -5,10 +6,6 @@
  *
  * Authors: Ruqiang Ju <juruqiang@hisilicon.com>
  *          Jianguo Sun <sunjianguo1@huawei.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/clk.h>