PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions.  No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pcie/aspm.c

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * File:	drivers/pci/pcie/aspm.c
- * Enabling PCIe link L0s/L1 state and Clock Power Management
+ * Enable PCIe link L0s/L1 state and Clock Power Management
  *
  * Copyright (C) 2007 Intel
  * Copyright (C) Zhang Yanmin (yanmin.zhang@intel.com)