irq-gic: remove file name from heading comment

File names in the heading comments  fell out of favor long ago, and this one
weren't even changed when the driver was moved from arch/arm/common/, so remove
it at last...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/irqchip/irq-gic.c

 /*
- *  linux/arch/arm/common/gic.c
- *
  *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify