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>
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 7815768..1abdbf2 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * File:	pci-acpi.c
- * Purpose:	Provide PCI support in ACPI
+ * PCI support in ACPI
  *
  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>